JP2006164218A - Storage system and its cache control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance performance by increasing a cache hit rate. <P>SOLUTION: A storage control node is equipped with a means for managing in which cache node the control right is given relating to a specific area in corresponding address space of a storage device connected to the storage control node. The cache node receives data request from a host device and retrieves the cache. At the time of cache hit, the data request is processed by employing the cache area. At the time of miss hit, a specific control right is requested to an appropriate storage control node. When the cache node having the control right exists, the data request from the host device is processed by employing the cache area of the node through the medium of exclusive processing by the cache node having the control right. When cache node having the control right does not exist, provision of the control right to the cache node at the request origin is registered to be notified. The cache node provided with the control right executes cache control by the cache of the cache node. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cache control technique and a storage system, and more particularly to a system and a cache control method that are suitable when applied to cache control of a distributed system.

  A storage system represented by a disk array device is provided with a cache memory to buffer the slow access speed of a storage device such as a magnetic disk device and improve performance such as the number of inputs / outputs per unit time and throughput. Yes.

  Since the frequently accessed area is limited in the total capacity of the disk array device, the response to the host computer can be speeded up by temporarily storing the data in the cache memory. Can do.

  In such a disk array device, a multi-director type storage system is known in which a plurality of director units that perform processing from a host computer and input / output processing to a storage device are mounted.

  As publications relating to such a disk array device, the descriptions of Patent Documents 1 and 2 below are referred to.

  In the storage system described in Patent Document 1 described later, in a disk array device including a plurality of directors and a shared memory, control is performed to reduce the number of accesses to the shared memory. The storage system described in Patent Document 1 includes a host director, a disk director, and a shared memory having a cache page unit that temporarily stores input / output data communicated between the host computer and the host director. Has a local memory. This storage system operates as follows.

  That is, when each host director receives a data request from the host computer, the host director performs exclusive control on the corresponding cache page in the shared memory so that it is not operated by another director during data transmission / reception. Even after the data request is processed, the cache page is managed in the cache control area provided in the local memory of each host director, and only the local host director releases it and continues to access the cache page. In such a case, access to the shared memory is omitted, the local host director is set to use and processed, and the cache page is used.

  However, in such a configuration, the shared memory is accessed from a plurality of directors. To use cache pages that are not managed by the director, it is necessary to access and process the shared memory, and the size of the disk array device is large. When it comes to, access conflicts. Even in the cache page managed by its own director, since the cache page is in the shared memory, access to the cache page takes time corresponding to the path to the shared memory. It is difficult to speed up the time particularly.

  In other words, the latency to the shared memory is large, and when access to the shared memory is concentrated, the performance is deteriorated. Further, if the access concentration is distributed, the configuration is enlarged.

  The storage system described in Patent Document 2 described later is a disk array system that has a large-scale configuration by increasing the number of host directors and disk directors. Such a disk array system includes a plurality of host directors that communicate with a host device, a cache memory connected to each host director, one or more disk directors connected to one or more disks, and a host. It includes one or more network means for connecting the director and the disk director, and operates as follows.

  That is, the host director that has received a data read request or data write request from the host computer sends a data request to the disk director when there is no requested data in the cache memory connected to the host director, The disk director that has received the data request examines recording information indicating that the data read from the disk drive connected to the disk director is stored in the cache means connected to which host director of the plurality of host directors. If the requested data has never been sent to another host director, the disk director reads the data from the disk and sends it to the host director. The host director stores the received data in the cache memory, and if it is a data write request, writes the write data received from the host computer to the cache memory to make a change. Transfer data.

  If the requested data has been sent to another host director, the host director is made to invalidate the data. At that time, if the data has been rewritten and has not been written back to the disk, the disk director receives the rewritten data via the host director and newly reads it from the disk. Overwrite the data and then send the data to the host director.

  The host director stores the received data in the cache memory and writes the write data received from the host computer into the cache memory for modification.

  If the data has not been rewritten, the data is invalidated and the data newly read from the disk is sent to the requesting host director.

The host director stores the received data in the cache memory, and if it is a data write request, writes the write data received from the host computer to the cache memory for modification, and if it is a data read request, the data in the cache memory Forward.
As a technique for specifying a unit that performs input / output control for a target storage volume in response to an input / output request, for example, Patent Document 3 described later includes a host interface control unit for receiving a data input / output request. A channel control unit, a disk control unit formed with a disk interface control unit for performing data input / output control on a storage volume for storing data in response to the data input / output request, and the data A cache memory unit in which a memory for storage is formed; a mounting unit in which the storage control unit in which the host interface control unit, the disk interface control unit, and the memory are formed; and the channel control unit; The disk control unit, the cache memo A storage unit that is communicably connected to the storage control unit, and the storage unit that is the target of the data input / output request to at least the memory of the storage control unit. A method of controlling a storage device control apparatus to which a plurality of storage control units are mounted, in which information for specifying the unit that performs the input / output control is stored.
The storage control unit receiving the data I / O request;
The storage control unit refers to the information and identifies the unit that performs the input / output control for the storage volume that is the target of the input / output request;
When the unit that performs the input / output control is the storage control unit, the storage control unit performs the input / output control, and when the unit that performs the input / output control is not the storage control unit, The storage control unit comprises a step of performing the input / output control. A method for controlling a storage device control apparatus is disclosed.

JP 2003-228461 A JP 2003-345520 A JP 2004-318484 A

  In the conventional storage system described above, data read time from the disk, invalidation processing between the host director and the disk director, and the like become bottlenecks.

  In a storage system with multiple host directors, when a host director that receives a data request from a host makes a cache miss in its own cache, it uses a cache page that is held or managed by another host director. It has the problem that it cannot be done.

  This is because the conventional storage system does not consider use of a cache page held or managed by a director by another director.

  In a storage system composed of a plurality of host directors having a cache means, a disk director, and a network means for connecting the host director and the disk director, the number of inputs / outputs per unit time cannot be greatly improved. have.

  The reason is that it takes time to read the disk when a cache miss occurs in a certain host director. Furthermore, if the data read from the disk is stored in the cache means of another host director, it takes time to control consistency.

  In a storage system composed of a plurality of host directors having cache means, disk directors, and network means for connecting the host directors and disk directors, the director's capacity can be increased in accordance with the expansion and increase of storage space and the number of connected host devices. When the number becomes large, it is difficult to improve performance such as the number of inputs / outputs per unit time and data transfer speed.

  The reason is that, when a cache miss occurs in each host director, the disk director reads the disk, so that when the number of host directors becomes large, the concentration of disk director access occurs.

  Accordingly, a main object of the present invention is to provide a cache control system, a storage system, and a cache control method that improve cache utilization efficiency.

  Another object of the present invention is to provide a cache control system, a storage system, and a cache control method capable of reducing latency and avoiding resource contention and improving performance while achieving the above object.

  Another object of the present invention is to provide a cache control system, a storage system, and a cache control method that eliminate the number of accesses to the storage device and greatly improve the performance of the number of inputs / outputs per unit time and the data transfer rate for the host device. Is to provide.

  Still another object of the present invention is to provide a cache control system, a storage system, and a cache control method that can be expanded and increased in accordance with the expansion and increase of the storage space and the increase of host devices, and the performance can be improved.

  In order to achieve the above object, the invention disclosed in the present application is typically summarized as follows.

  A cache control system according to one aspect of the present invention includes a cache memory for storing information of a storage device, and a plurality of processing units, and has a control right for a specific area of an address space to be cached. If the first processing unit has at least one processing unit (referred to as a “management processing unit”) that manages which processing unit has, and the first processing unit does not have control over the data to be processed, the first processing The unit includes means for transmitting a first signal including information on the corresponding control right to the management processing unit, and the management processing unit stores which processing unit currently holds the corresponding control right. When there is a means for searching for a processing unit that holds the control right with reference to a storage unit to be managed, and a second processing unit that holds the control right as a result of the search, A second signal including information on the control right to a second processing unit, and the second processing unit receives the second signal from the management processing unit, The first processing unit includes means for giving information for accessing a cache area in a specific cache memory, and the first processing unit accesses a cache area to be processed based on the given information. .

  In the cache control system according to the present invention, the second processing unit that holds the control right receives the second signal from the management processing unit, and in a specific cache memory that is determined from the second signal. The cache area is exclusively processed, and the access information of the cache area is given to the first processing unit.

  In the cache control system according to the present invention, the management processing unit grants the control right to the first processing unit when there is no processing unit holding the control right as a result of the search. Means to do.

  In the cache control system according to the present invention, the plurality of processing units may be configured by nodes connected via communication means, and the cache memory may be provided for each node.

  In the cache control system according to the present invention, the plurality of processing units include a plurality of nodes connected via communication means, and the cache page is stored in a shared memory shared by the plurality of nodes, and cache control information May be stored for each node.

  In the cache control system according to the present invention, the first processing unit may have a means for specifying a management processing unit.

  In the cache control system according to the present invention, the management processing unit searches for control information storing a correspondence between specific address information in an address space and a processing unit holding a control right determined from the address information. Thus, the processing unit that holds the control right may be specified.

  A storage system according to another aspect of the present invention includes a plurality of cache nodes that control input / output with a host device and have a cache function, a plurality of storage control nodes that control input / output with the storage device, Network means for interconnecting the plurality of cache nodes and the plurality of storage control nodes, and means for managing a correspondence relationship between the control right and a cache node for a specific area of a logical address space. Have.

  In the storage system according to the present invention, a certain cache node searches the cache with the cache node, and if there is a cache, uses the corresponding cache area to process the data request of the host device, and the cache node stores the cache. If there is no cache node, the required storage control node is requested, and if there is a cache node having the control right, the cache node performs exclusive processing, and the corresponding cache area of the cache node having the control right is determined. If there is no cache node that has the control right, it registers and notifies that the corresponding control right has been given to the requesting cache node. Cache control with node cache.

  A method according to one aspect of the present invention includes a plurality of cache nodes having cache means, which are connected to a host device and perform input / output processing, a plurality of storage devices, and an input / output connected to the plurality of storage devices. A storage system cache control method comprising: a plurality of storage control nodes that perform processing, wherein the storage control node determines which cache node has control over a specific area of a logical address space. Including the process of managing.

In the method according to the invention,
The cache node receiving a data request from the host device and searching the cache with the cache node;
When it is determined that there is a cache, the cache node includes a step of performing data access using a corresponding cache area.

In the method according to the present invention, when it is determined that there is no cache,
The cache node requests a predetermined control right from the corresponding storage control node, and when there is a cache node having the control right, the cache node having the control right performs exclusive processing, and the cache node having the control right Processing the data request of the host device using the corresponding cache area of
If there is no cache node having the control right, the cache node registers and notifies the specific storage control node that the corresponding control right has been given to the requesting cache node; and
The cache node to which the corresponding control right is given includes a step of performing cache control with the cache of the cache node.
According to yet another aspect of the present invention, a cache control system having at least one cache memory and a plurality of processing units, which is uniquely determined from an address of predetermined data in an address space to be cached A processing unit (referred to as a “management processing unit”) that manages which processing unit has control authority with respect to a unit area, and at least one processing unit of the plurality of processing units is a unit to which the processing unit is an access target And a means for issuing a request to the management processing unit to search for a processing unit having the control right for the unit area, when the management processing unit has no control right for the region, In response to the request from, a search is made as to which processing unit currently has the right to control the unit area, and as a result of the search, there is a processing unit having the right to control the unit area. The processing unit having the right to control the unit area is provided with means for notifying the processing unit that has issued the request, the processing unit having the right to control the unit area from the management processing unit. In the case of read access, the cache memory data corresponding to the data in the unit area is supplied to the processing unit that issued the request. In the present invention, in the case of write access, the processing unit that has issued the request notifies the processing unit having the control right of the unit area that has received the notification information from the management processing unit to start transfer and writes Transfer data.
According to yet another aspect of the present invention, a cache control system having at least one cache memory and a plurality of processing units, which is uniquely determined from an address of predetermined data in an address space to be cached A processing unit (referred to as a “management processing unit”) that manages which processing unit has control authority with respect to a unit area, and at least one processing unit of the plurality of processing units is a unit to which the processing unit is an access target And a means for issuing a request to the management processing unit to search for a processing unit having the control right for the unit area, when the management processing unit has no control right for the region, In response to the request from, a search is made as to which processing unit currently has the right to control the unit area, and as a result of the search, there is a processing unit having the right to control the unit area. If you, the processing unit that issued the request, and a means for notifying the information processing unit having a control right of the unit region.
In the present invention, the processing unit that issued the request receives the notification information from the management processing unit, and in the case of read access, transmits a usage notification to the processing unit having the right to control the unit area, and The processing unit having the control right of the unit area that has received the usage notification may transfer the data in the cache memory corresponding to the data in the unit area to the processing unit that issued the request.
In the present invention, the processing unit that issued the request receives the notification information from the management processing unit, and transfers write data to the processing unit having the right to control the unit area in the case of write access. May be.
In the present invention, the processing unit that issued the request receives the notification information from the management processing unit, inquires the processing unit having the control right of the unit area, and the processing unit having the control right of the unit area is In response to the inquiry, the address information of the data of the unit area to be accessed is notified, and the processing unit that issued the request uses the address information notified from the processing unit having the control right of the unit area, You may make it access the data of the said unit area | region of access object.

  According to the present invention, the configuration includes a plurality of cache nodes, and the control is performed so that the caches possessed by each of the plurality of cache nodes are used. The hit rate can be increased and the performance can be improved.

  According to the present invention, the number of accesses to the storage device can be omitted, and the performance of the number of inputs / outputs per unit time and the data transfer rate can be greatly improved with respect to the host device. The reason for this is that if the own processing unit has the right to control the corresponding cache for the data input / output request of the host device, the host device can control the data input / output request of the host device without communicating with other processing units. Even if there is no control right for the corresponding cache, if there is a control right for the cache corresponding to another processing unit, access to the extra storage device can be omitted, and the control right for the cache corresponding to all the processing units This is because even if there is no request, if the request is a write request, the processing unit that has received the request can write to the cache without accessing the storage device.

  Furthermore, according to the present invention, it is possible to provide a storage system that can be expanded and expanded in accordance with the expansion and increase of the storage space and the increase of host devices, and the performance can be improved. The reason is that it can be expanded on a node-by-node basis, and if the cache hit rate of its own cache node is high, the number of times of communication to other nodes can be greatly reduced. If there is a cache in the cache node, it can be used, so when the number of nodes increases, access concentration increases and access to the storage device that becomes a performance bottleneck can be omitted, and all cache nodes have no cache Even in this case, since a write request can be written to the cache of the cache node that received the request, the access concentration increases when the number of nodes increases, and access to the storage device that becomes a performance bottleneck can be omitted. Because.

  In order to describe the present invention described above in further detail, this will be described with reference to the accompanying drawings. First, the principle of the present invention will be described. The present invention achieves performance improvement (number of I / O processing per unit time, data transfer amount) by improving cache utilization efficiency through cooperative control with other nodes, eliminating resource contention, and reducing latency, It is intended to achieve both improvement in performance and prevention of scale-up. FIG. 1 is a diagram for explaining the principle of the present invention. FIG. 1 shows a distributed memory in which a plurality of processing units forming a processing unit are distributed in a plurality of nodes connected to each other via communication means and the like, and a cache area is distributed and held in a plurality of nodes It is a figure which shows the structure principle of this cache control system.

  In the embodiment of the present invention, access from the upper processing means is controlled by a logical address space in the system. It is assumed that there is data identification information determined based on an agreement with the upper processing means when accessing from the upper processing means. The host processing means accesses data in a specific address space using the data identification information. Each node caches data to be processed when it has a control right regarding a unit area (referred to as “chunk” in this specification) uniquely determined from data identification information in a logical address space in the system. If you do not have control right, perform cooperative control with other nodes.

  The data accessed by the upper processing means is temporarily stored in the cache area in the present system, but is finally stored in the storage device as the lower processing unit. Therefore, the correspondence between the address of the area in the logical address space in the system and the address of the area in the storage device is stored as management information in the cache control system. Note that the cache control information of each cache area is provided in each node provided with the cache area.

  Referring to FIG. 1, in the processing unit 1 in one node that may receive an access request from the host processing means 1, the control unit has no control right for the corresponding chunk of the processing target data (when a chunk miss occurs) ), The processing unit 1 transmits a first signal including information for identifying the corresponding chunk or specific data in the corresponding chunk to the management processing unit (request of Step 1).

  In FIG. 1, since a node with a management processing unit is a different node from the processing unit 1, the first signal is transmitted via the mutual communication means (the management processing unit and the processing unit 1 exist in the same node). If so, you can do it inside the node). The first signal may include information indicating that a control right for the corresponding chunk is requested. When the processing unit 1 has the control right for the corresponding chunk, the processing unit 1 applies another processing unit to the cache area in the same node as the processing unit 1 corresponding to the corresponding chunk or specific data in the corresponding chunk. Can be accessed without communication.

  The management processing unit that has received the first signal from the processing unit 1 refers to the storage unit that stores and manages the control unit that holds the control right for the specific chunk, and holds the control right for the corresponding chunk. If there is a processing unit having a control right for the corresponding chunk, the corresponding chunk or the corresponding chunk is assigned to the processing unit holding the control right (referred to as “processing unit 2”). A second signal including information for identifying specific data is transmitted (permission instruction in step 2). In FIG. 1, since a node with the processing unit 2 is a different node from the management processing unit, a second signal is transmitted via the mutual communication means or the like (the processing unit 2 and the management processing unit exist in the same node). If so, you can do it inside the node).

  The processing unit 2 receives the second signal from the management processing unit, and gives the processing unit 1 information for accessing the cache area corresponding to the corresponding chunk or specific data in the corresponding chunk (step 3). Use permission).

  The processing unit 1 accesses the corresponding cache area of the cache memory in the node including the processing unit 2 based on the information given from the processing unit 2 (input / output in step 4).

  When the processing unit 2 receives an instruction from the management processing unit and gives access information to the processing unit 1, the processing unit 2 performs an exclusive process on data update to the corresponding cache area (however, the use permission of step 3 is issued). The corresponding cache area is controlled so that only the processing unit 1 can update it. That is, when the processing unit 1 updates the corresponding cache area, other processing units cannot update the cache area. For example, after performing an exclusive process on the data in the cache area, if the processing unit 2 receives an update access request for data related to the cache area from the higher-level processing means 2, the processing unit 2 uses the exclusive cache area. The update process for the request is not executed at the same time, and consistency is maintained.

  After the processing of the corresponding cache area is completed, the processing unit 1 notifies the processing unit 2 of the use cancellation. The processing unit 2 receives the notification of cancellation of use and releases the exclusion. In FIG. 1, the upper processing means is shown outside a node having a processing unit. However, the upper processing means may be on the same node as the processing unit, and the upper processing means 1 and the upper processing means 2 are It may be the same. These can be similarly applied to the embodiment described below with reference to FIG.

  FIG. 2 is a diagram for explaining the principle of the present invention, as in FIG. 1. FIG. 2A is for explaining the principle of cache page access control in one computer system such as an information processing apparatus. FIG. FIG. 2B is a diagram illustrating a configuration in which a cache page is provided in a shared memory. In the configuration of FIG. 2A, the cache control information is provided in the computer to which each processing means belongs, and a dedicated memory area is assigned to each processing means. In the configuration of FIG. 2B, the cache control information is provided for each node provided with a processing unit that processes an access request from the higher-level processing means, and a plurality of processor nodes communicate via the mutual communication means. Applied to distributed systems

  More specifically, referring to FIG. 2A, when a certain processing means 1 (which may be a process or a processor) in a computer system does not have a control right for the corresponding chunk, the processing means 1 The first signal including information for identifying the corresponding chunk or specific data in the corresponding chunk is transmitted to the management means for managing which processing means has the control right for the corresponding chunk (step 1 request).

  The management means that has received the first signal refers to the storage unit that stores and manages the processing means that holds the control right for the specific chunk, searches for the processing means that holds the control right for the corresponding chunk, A second signal including information for identifying the corresponding chunk or specific data in the corresponding chunk is transmitted to the processing means 2 holding the control right for the chunk (permission instruction in step 2).

  The processing means 2 receives the second signal from the management means, and gives the processing means 1 information for accessing the cache area corresponding to the relevant chunk or specific data in the relevant chunk (in step 3). License).

  The processing means 1 accesses the cache area to be processed based on the given information (input / output in step 4).

  When the processing unit 2 receives the second signal from the management unit and gives access information to the processing unit 1, the processing unit 2 performs exclusive processing on the target cache area (before issuing the use permission in step 3), The corresponding cache area page is controlled so that only the processing means 1 can update it.

  The processing unit 1 notifies the processing unit 2 of the cancellation of use after the corresponding cache processing is completed. The processing means 2 receives the notification of cancellation of use and releases the exclusion.

  In FIG. 2A, the principle of cache control in one computer system having a plurality of processing means has been described. However, a configuration in which a plurality of processors and a shared memory are interconnected and a cache area is provided in the shared memory is also possible. The cache control of the present invention can be applied.

  Next, referring to FIG. 2 (B), when one processing unit 1 does not have the control right for the corresponding chunk, the processing unit 1 sends the management processing unit to the corresponding chunk or the corresponding chunk. A first signal containing information identifying specific data is transmitted (request of step 1).

  The management means that has received the first signal refers to the storage unit that stores and manages which processing means holds the control right for which chunk, and determines the processing means that holds the control right for the corresponding chunk. The second signal including information for identifying the corresponding chunk or specific data in the corresponding chunk is transmitted to the processing unit 2 that searches and holds the control right for the chunk (permission instruction in Step 2).

  The processing unit 2 receives the second signal from the management processing unit, and gives the first processing unit information for accessing the cache area corresponding to the corresponding chunk or specific data in the corresponding chunk ( Permission to use step 3).

  The processing unit 1 accesses the corresponding cache area in the shared memory based on the information given from the processing unit 2 (input / output in step 4).

  The principle of the present invention has been described above in accordance with each system configuration. In the following, the cache control process when a chunk miss occurs in the processing unit 1 of FIG. 1 will be described with reference to the flowchart of FIG. .

  In step S1, the processing unit 1 transmits a first signal including information for identifying a chunk corresponding to the management processing unit that manages the control right of the chunk to be processed or specific data in the corresponding chunk.

  In step S <b> 2, the management processing unit that has received the first signal searches for a processing unit that holds a control right for the corresponding chunk.

  In step S3, if there is no processing unit that holds the control right for the chunk, the management processing unit assigns the control right for the chunk to the processing unit 1 and stores the correspondence between the chunk and the processing unit that holds the control right. Save to the storage unit to be managed.

  In step S <b> 4, the management processing unit notifies the processing unit 1 that control right related to the chunk is given.

  In step S5, the processing unit 1 that has received the notification of granting the control right prepares cache area allocation and exclusive processing necessary for operating the cache related to the data request of the upper processing means. After the completion of this process, the processing unit 1 performs a read process or a write process on the cache area.

  In step S6, if there is a processing unit 2 that holds the control right for the chunk, the management processing unit that has searched in step S2 sends the processing unit 2 the corresponding chunk or the corresponding chunk. A second signal containing information identifying specific data within is transmitted.

  In step S7, the processing unit 2 that has received the second signal prepares for allocation of the cache area corresponding to the corresponding chunk determined from the second signal or specific data in the corresponding chunk, or for exclusive processing. Do. When the processing unit 1 accesses the corresponding cache area, the processing unit 2 and other processing units cannot access the cache area. When the processing unit 1 performs reference access, only the reference may be permitted to other processing units. When the processing unit 2 receives the second signal and the processing unit 2 is currently using the cache area, the processing unit 2 uses the second signal as an access request of the processing unit 1, and Similar to the cache control related to the data request from the processing means, it is managed as a wait related to the cache area, and after the use is completed, the process of step S8 is performed. Further, a wait (WAIT) signal related to the corresponding cache page may be given to the processing unit 1 without being managed as a wait.

  In step S8, the processing unit 2 gives the processing unit 1 information for accessing the cache area corresponding to the corresponding chunk or specific data in the corresponding chunk.

  When the process in step S8 ends normally, the processing unit 1 performs a read process or a write process on the cache area in the local memory of the processing unit 2.

  According to the present invention, even when the cache does not hit the local node, if there is a cache page corresponding to the other node, the access to the storage device can be omitted by using the cache page of the other node. Can contribute to speeding up. In addition, by performing cache control at each cache node, the amount of communication between nodes can be reduced, which contributes to higher speed. Hereinafter, description will be made with reference to examples.

  FIG. 4 is a diagram showing the configuration of the first exemplary embodiment of the present invention. Referring to FIG. 4, the first embodiment of the present invention controls a plurality of cache nodes 2a having a cache function for controlling input / output with a host device such as a host computer and temporarily storing the input / output data. 2b, 2c, 2d, storage control nodes 3a, 3b, 3c, 3d for controlling input / output with the storage device that finally records and stores data, a plurality of cache nodes 2a, 2b, 2c, 2d, And a mutual communication means 4 through mutual communication between the plurality of storage control nodes 3a, 3b, 3c, 3d. The storage system 1 includes a configuration and one or more storage devices connected to each storage control node.

  In FIG. 4, for simplicity, the configuration includes four cache nodes and storage control nodes, but the number is not particularly limited. The intercommunication means 4 may be a bus, SCSI, LAN (Local Area Network), SAN (Storage Area Network), the Internet network, or any other suitable communication means. Further, the number of host devices and the number of storage devices are not particularly limited. The storage device may be a disk unit composed of a plurality of disk drive groups, or may be a disk array device or the like. Further, a storage device may be provided for each storage control node, and the storage control node and the storage device may be interconnected.

  In this embodiment, the control right assigned to a specific cache node is shared and managed by the storage control nodes 3a, 3b, 3c, and 3d to which cache node a certain control right is assigned. At this time, the unit area of the control right to be allocated is the same size as the page and is incorporated into the cache control system, so that the processing associated with the control right and the information for managing the control right are shared, and the entire process Can be simplified. The control right of this embodiment corresponds to the control right of a specific chunk described with reference to FIGS. A node having the control right can perform cache control without communicating with other nodes. On the other hand, when there is a cache node with control right, a cache node without control right reads out the corresponding cache page of the node with control right by performing a predetermined operation. And write. If no control right exists in any of the cache nodes, the control right is given to the node that inquired the control right, that is, the node that first received the data read request or write request from the host device. give. This is realized by writing information indicating which cache node has the control right to the storage control node, and securing a cache page for the cache node that has inquired the control right. After assigning the control right, the node that has received the data read or write request from the host device receives the data from the host device in the cache page in the case of a write request, and via the storage control node in the case of a read request The data corresponding to the read request is received from the storage device in its own cache page, and then transferred to the host device.

  In the example shown in FIG. 4, when the cache nodes 2a, 2b, 2c, and 2d having a cache function receive a data read request or a data write request from a higher-level device, local caches in their own cache nodes (in FIG. 4) The management information of the cache of the control memory unit stored in a not-shown (described later with reference to FIG. 5) is checked, and whether or not the corresponding cache page exists in the cache page storage unit in the own cache node. Search for. Specifically, the cache control unit 113 searches for the page tag of the cache control information (see FIG. 23) stored in the control memory unit 121 on the local memory 12, so that the cache page of the request has already been cached. It is determined whether the page portion 122 exists.

  FIG. 23 is a diagram illustrating a configuration example in the cache control information stored in the control memory unit 121 on the local memory 12. Referring to FIG. 23, the cache control information shown in one embodiment of the present invention includes a configuration in which a plurality of page tags 31 are managed by a hash table 30 in order to speed up processing at the time of search. . In addition, the cache control information includes management information such as an empty page and a page with write data not saved in the storage device (not shown).

  FIG. 24 is a diagram illustrating an example of the configuration of a page tag. The page tag 31 of FIG. 23 includes information as shown in FIG. 24, and the page address 41 indicating the storage position of the cache data on the cache page unit 122 and the cache page indicated by the page address 41 are higher-order. Link the address information 40 indicating whether it is cache data of the logical address existing on the storage system specified by the device, or the address obtained after the unique conversion of the logical address, and the page tags 31, It consists of a pointer 42 and the like for operating and searching the page tag 31. The page tag 31 is managed by a hash table 30 for speeding up the processing at the time of search. When searching whether the cache page is in the cache page 122, a hash function is calculated from the address information of the request to determine which table in the hash table 30 is to be searched. The calculation by this hash function is uniquely determined from the given address information, and the same address information indicates the position of the same table. As a result of the calculation by the hash function, the address information of the page tag 31 combined with the determined table is compared, and the address information 40 connected to the table does not match, or the page tag connected to the table If there is no 31, the data of the logical address that has received the search request does not exist in the cache page unit 122, and if the page tag 31 that matches the address information 40 exists, the data of the logical address that has received the search request is , The cache page unit 122 exists.

  In the present embodiment, if the data of the logical address that has received the above search request exists in the cache page unit 122, the cache node has the control right of the area indicated by the address information 40 of the cache page and exists. If there is no control right, the state having no control right is defined, the process related to the control right is transferred to the cache process, and the control right information is transferred to the cache information, thereby simplifying the control right process.

  When a corresponding cache page is found in a cache node that has received a data read request or data write request from the host device, the cache node has control over the cache page, and the cache node If it is a data read request, the node only has to transfer data from the cache page to the host device, and a high-speed response to the host device is possible. If the request is a data write request, when the data is written to the cache page, the processing completion is returned to the host device, and the data is written to the storage device after the processing is completed. It becomes.

  On the other hand, in a cache node that has received a data read request or a data write request from a higher-level device, if the corresponding cache page does not exist in the cache node, the cache node is notified to the management node that manages the control right. If there is a control right holding node for the page, the cache node that has accepted the request can transfer data from the cache page of the control right holding node via the mutual communication means 4 if it is a data read request. Better, a much faster response is possible than reading data from the storage device. Even if it is a data write request, when the write data from the host device is written to the corresponding cache page of the control right holding node via the mutual communication means 4, the processing is completed for the host device. Returning and writing the data to the storage device later prevents access to the storage device, so that high-speed response is possible.

  FIG. 5 is a diagram showing the configuration of the cache nodes 2a, 2b, 2c, and 2d in FIG. Note that the cache nodes 2a, 2b, 2c, and 2d in FIG. Referring to FIG. 5, the cache node 2 includes a host device interface unit 10, a data processing device 11 that operates by program control and serves as a main control unit, a local memory 12, and a controller 13.

  The host device interface means 10 is connected to one or more host devices via the connection paths 5a, 5b, 5c, and 5d, receives data read requests or data write requests from the host device, and Processes data input and output with the cache node. The cache node may be provided with a plurality of higher-level device interface means, and an interconnection means such as a switch may be used for connection with the higher-level device.

  The data processing device 11 includes command control means 111, management node specifying means 112, and cache control means 113. The command control unit 111 determines each command of a data read request or a data write request from the host device received by the host device interface unit 10 and controls processing according to each command.

  The management node specifying unit 112 specifies a management node to communicate when there is no cache page to be read / written in the own cache node.

  The cache control unit 113 manages and controls the cache search process and the cache stored in the local memory 12.

  The local memory 12 includes a control memory unit 121 and a cache page unit 122, and is configured by a semiconductor memory that can be accessed at a higher speed than the storage device. There may be a plurality of local memories 12, and the control memory unit 121 and the cache page unit 122 may be provided in different local memories.

  The control memory unit 121 stores storage space configuration information (see FIG. 6) indicating to which storage control node a logical storage space is allocated, cache management information, and cache node control information.

  The cache page unit 122 temporarily stores data input / output to / from the host device via the host device interface unit 10 in units of pages.

  The controller 13 controls data communication of the cache node 2 and also processes communication with other cache nodes and storage control nodes via the mutual communication means 4. A cache node may include a plurality of controllers.

  FIG. 6 is a diagram showing the configuration of storage space configuration information indicating to which storage control node a logical storage space (logical volume) recognized by the storage system 1 is assigned. In this embodiment, a storage control node to which a logical storage space of a certain logical volume number is assigned is a management node.

  The management node specifying unit 112 in FIG. 5 can determine to which storage control node a logical storage space of a certain logical volume number is assigned by referring to the storage space configuration information, and specify the management node. it can. Instead of the storage space configuration information stored in the control memory unit 121, configuration information indicating to which storage control node a unit obtained by dividing a specific logical storage space into a predetermined size may be stored. . In this case, the management node specifying unit 112 can determine the division unit to which the data requested by the higher-level device belongs, and can refer to the configuration information to determine which storage control node the division unit is assigned to. Can be specified.

  Next, the storage control node will be described with reference to FIG. Each storage control node 3a, 3b, 3c, 3d has the same configuration. The storage control node 3 includes a storage device interface unit 20, a data processing device 21 that operates by program control and serves as a main control unit, a local memory 22, and a controller 23.

  The storage device interface unit 20 is connected to one or more storage devices via the connection paths 6a, 6b, 6c, and 6d, and inputs and outputs data between the storage device and the storage control node.

  The data processing device 21 includes a storage device control unit 212 and a control right management unit 211.

  The storage device control unit 212 controls input / output command processing to the storage device that finally records and stores data.

  The control right management unit 211 executes a processing request for the control right from the cache nodes 2a, 2b, 2c, and 2d.

  The local memory 22 includes a control memory unit 221 and is configured by a semiconductor memory that can be accessed faster than the storage device.

  The control memory unit 221 stores storage control node control information and storage system 1 device configuration information. Further, the control memory unit 221 has control right management information indicating which node has the control right for a specific cache page unit uniquely determined from the addresses in all logical storage spaces recognized by the storage system 1. Stored.

  The controller 23 controls data communication of the storage control node, is connected to the mutual communication means 4, and controls communication with other cache nodes and storage control nodes. The storage control node may include a plurality of controllers.

  8 and 9 are diagrams showing the configuration of the control right management information stored in the control memory unit 221 of the local memory 22 in FIG.

  The control right management information stored in the control memory unit 221 constitutes a table in which the logical address of the area allocated for each cache page unit and the node number having the control right of the area correspond to each other.

  Thereby, when a certain logical address is indicated, the control right management unit 211 checks whether the area to which the logical address belongs is in the control right management information, and whether there is a cache node having the control right for the corresponding area. If there is a node having the control right, the cache node can be specified. The control right management unit 211 performs processing according to this determination.

  If there is no cache node having the control right, a new control right is set, registered in the control right management information, and notified to the node that has registered the control right.

  When there is a cache node having the control right, a predetermined instruction is given to the cache node having the control right.

  Next, the operation of the first embodiment of the present invention will be described in detail. FIG. 10 is a flowchart for explaining the processing operation of the first embodiment of the present invention.

  Hereinafter, a case where the cache node that receives a data read request or a data write request from the host apparatus is the cache node 2a will be described as an example.

  The cache node 2a in FIG. 4 receives a data read request or data write request command from the host device via the connection path 5a by the host device interface means 10 (see FIG. 5).

  When the cache node 2a receives the command, the command control unit 111 (see FIG. 5) analyzes the request.

  Then, the cache control unit 113 (see FIG. 5) receives the analysis result of the command control unit 111, and determines whether or not the cache page corresponding to the requested data already exists in the cache page unit 122. 5) The above cache control information (see FIG. 23) is searched and determined.

  Specifically, the logical address specified by the command received by the command control unit 111 is an address corresponding to 1000 in the page tag address information, and the content of the cache control information of the cache node 2a at that time is: Assume that the state shown in FIG. The cache control unit 113 of the cache node 2a calculates a hash function and determines one table on the hash table. When the calculation of the hash function is “5”, it is searched whether there is a matching page tag while comparing the address information 40 of the page tag connected to the table “5”.

  If the contents of the cache control information at this time (see FIG. 23) are as shown in FIG. 25, the first page tag connected to the table has the address information “1000”. Since the data corresponding to the logical address specified by the command received in step S1 exists on the cache page unit 122 (see FIG. 5), the cache node 2a that has received the command has the control right. The cache page can be accessed without communicating with the cache node.

  After that, after exclusive processing of the cache page so that it is not operated by other processing, the cache node 2a immediately reads the corresponding data from the cache page on the cache page unit 122 if it is a data read request, Transfer to host device.

  If it is a data write request, the data sent from the host device is written to the corresponding cache page on the cache page unit 122. Since each process does not require communication with other nodes, it can be processed at high speed.

  Thereafter, the cache control unit 113 updates the cache management information of the control memory unit 121 necessary for efficient cache page management by the LRU (Least Recently Used) method and releases the exclusion.

  When the corresponding cache page does not exist on the cache page unit 122, processing according to the procedure shown in FIG. 10 is performed.

  FIG. 10 shows that in the first embodiment of the present invention, when a cache node receives a data read request or data write request from a host device and performs a cache search in its own cache node, the cache node has a cache. It is a flowchart which shows a process when it does not exist.

  First, the logical address specified by the command received by the command control means 111 of the cache node 2a is the address corresponding to 3000 in the page tag address information, and the cache control information (see FIG. 23) of the node 2a at that time is It is assumed that the content is as shown in FIG. The cache control unit 113 of the cache node 2a calculates a hash function and determines one table on the hash table. Assume that the calculation of the hash function is “5”. The cache control unit 113 compares the address information 40 (see FIG. 24) of the page tag connected to the five tables on the hash table on the cache control information (see FIG. 25). Since “3000” does not exist, the cache node 2a has no control right because the data corresponding to the logical address does not exist in the cache page portion.

  When the cache control unit 113 of the cache node 2a determines that it does not have the control right, the management node specifying unit 112 of the cache node 2a specifies the management node to which the control right request for the corresponding page should be notified (FIG. 10). Step A1).

  The management node specifying unit 112 can specify a storage control node that is a management node to which a control right request is to be notified with reference to the storage space configuration information (see FIG. 8) stored in the control memory unit 121.

  After specifying the corresponding management node, the controller 13 is instructed to notify, and the control right request is notified to the specified storage control node via the mutual communication means 4 (step A2 in FIG. 10).

  Here, a description will be given assuming that the control right management node that manages the assignment of control right to the requested data by the management node specifying unit 112 is the storage control node 3a.

  The storage control node 3a and the controller 23 (see FIG. 7) that received the notification of the control right request receive the control right request, the control right management unit 211 determines the control right request, and the control right determination Process.

  The control right management unit 211 searches the control right management information stored in the control memory unit 221 and determines whether there is a logical address of the corresponding page (step A3 in FIG. 10).

  Specifically, for example, the control right management information (see FIG. 8) includes a chunk identifier, a control right holding node number, and the like. In this embodiment, the chunk identifier is used as the address information of the page tag 31 (see FIG. 23). 40 (see FIG. 24) or an identifier uniquely determined from the address information is stored. The control right holding node number stores information indicating a cache node having the control right.

  Here, as an example, an example is shown in which the chunk identifier and the address information 40 (see FIG. 24) of the page tag 31 are the same. At this time, the address information received by the storage control node 3a is "3000", and the control management information held by the storage control node 3a has the contents shown in FIG. The control right management unit 211 searches for an item indicating “3000” in the chunk identifier of the control right management information (FIG. 8). As a result, there is no information with the chunk identifier “3000”, and it can be determined that no cache node has the control right.

  As described above, when there is no cache page control right holding node corresponding to the control right request data, a control right for the page area is newly granted to the requesting cache node 2a, and the control is performed. Registered in the right management information (step A4 in FIG. 10).

  Specifically, an item having a chunk identifier of “3000” is newly added to an empty area of the control right management information (see FIG. 8) of the storage control node 3a, and 2a is registered as the control right holding node number. (See FIG. 9).

  After registering the control right, the controller 23 is instructed to notify the cache node 2a, which is the requesting node, that the control right has been newly registered via the mutual communication means 4 (step A5 in FIG. 10). .

  The cache node 2a that has received the control right for the corresponding page secures the corresponding cache page in its own cache node and performs exclusive processing (step A6 in FIG. 10).

  Specifically, the cache control information possessed by the cache node 2a is as shown in FIG. 25, and the address information given the control right is “3000”. At that time, the cache control means 113 of the cache node 2a calculates a hash function and determines one table on the hash table. If the calculation of the hash function is “5”, the pointer of the page tag 31 (see FIG. 23) connected to the table “5” on the hash table is traced, and the page tag whose address information is “3000”. Add (link to the pointer of the page tag whose address information is “5000”), newly secure a cache page, and write the base address to the base address of the page tag whose address information is “3000” (see FIG. 26). ), The control right of the cache node 2a is established. Thereafter, an exclusive process of the cache page is performed in order to continue data reading or writing.

  Here, the cache node 2a has obtained the control right by the request from the host device, but the node voluntarily anticipates a continuous data read request without access from the host device, and the storage device previously Even in a prefetch cache operation for reading data into the cache, it is possible to obtain the same control right as in this sequence.

  Thereafter, if the request from the host device is a data read request, the control storage control node 3a is instructed to read the data from the storage device, is stored in the corresponding cache page of the cache node 2a, and is transferred to the host device .

  If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page, the processing completion is returned to the host device, and the data is written to the storage device later.

  After the request processing of the host device is completed, the cache control unit 113 of the cache node 2a updates the cache management information of the control memory unit 121 necessary for efficient cache page management by the LRU method and releases the exclusion. To do.

  In the processing for this write request, access to the storage device does not occur until a response is returned to the host device, so a high-speed response is possible.

  In step A3 of FIG. 10, when the control right management information is retrieved and there is a logical address of the corresponding page and there is a control right holding node, the storage control node 3a sends a control right request to the control right holding node. A request to use the corresponding cache page of the cache node 2a which is the original node is instructed (step A7 in FIG. 10).

  In the following description, it is assumed that the control right holding node is the cache node 2b based on the control right management information.

  Similar to the above description, the chunk identifier and the address information 40 of the page tag 31 will be described based on an example in which the same information is stored.

  Assume that the address information received by the storage control node 3a is "4000" and the control management information is as shown in FIG. The control right management unit 211 of the storage control node 3a searches for a chunk identifier in the control right management information (see FIG. 9) indicating “4000”. As a result, a cache page having a chunk identifier “4000” exists, and the corresponding control right holding node number 2b can be obtained.

  Thereafter, the control right management unit 211 of the storage control node 3 a instructs the controller 23 to notify, and notifies the cache node 2 b of the use request of the corresponding cache page via the mutual communication unit 4.

  The cache node 2b, which is the control right holding node of the corresponding cache page, receives the use request of the corresponding cache page of the cache node 2a from the storage control node 3a in the controller 13 of the cache node 2b, and the cache control means of the cache node 2b In step 113, exclusive processing is performed so that the corresponding cache page is not manipulated by other processing (step A8 in FIG. 10).

  Specifically, the address of the usage request received by the cache node 2b from the storage control node 3a is 4000, and the cache control information on the cache node 2b has the contents shown in FIG.

  The cache control unit 113 of the cache node 2b calculates a hash function and determines one table on the hash table. At this time, it is assumed that the calculated value of the hash function is 3. Compare the address information 40 of the page tag connected to the “3” table on the hash table of the cache control information (see FIG. 27), and since there is a page tag that matches with the address information “4000”, the cache The node 2b performs exclusive processing of the corresponding cache page.

  The cache control unit 113 of the cache node 2b sends the address information for accessing the cache page to the controller 13 of the cache node 2b after the exclusion process of the cache page to the cache node 2a that is the control right requesting node. The notification is instructed and notified through the mutual communication means 4. This is address information having contents including the page address 41 in the page tag whose address information of the cache control information (see FIG. 27) is “4000” (step A9 in FIG. 10).

  The cache node 2a that has received the notification of the address information for accessing the corresponding cache page thereafter transmits the data stored in the corresponding cache page of the cache node 2b to the upper level if the request from the higher-level device is a data read request. Transfer to device.

  If the request from the host device is a data write request, the cache node 2b writes the data sent from the host device to the corresponding cache page of the cache node 2b, returns processing completion to the host device, and To write the data to the storage device.

  In this process for the control right holding node, a high-speed response is possible because an access to the storage apparatus that requires a data response time does not occur until a response is returned to the host apparatus.

  Next, the function and effect of this embodiment will be described.

  In this embodiment, if the node has the necessary control right, the cache node can perform cache control in its own node without communicating with other nodes, thereby reducing the time required for processing the data request of the host device. Can do.

  Therefore, high-speed response is possible, and input / output performance per unit time can be greatly improved.

  Further, in this embodiment, even when there is no corresponding cache page in each cache node, when the control right is requested to the corresponding storage control node, the storage control node searches for the control right, When there is a corresponding control right holding node, the control right holding node performs exclusive processing on the cache page and notifies the access information, so that the cache page of the control right holding node can be used even in a cache node where the cache page does not exist.

  For this reason, there is no access to the storage device and a high-speed response is possible.

  Furthermore, even when there is no corresponding control right holding node, the control right is granted to the requesting cache node, the cache page can be used exclusively immediately, and if it is a data write request, it is transferred to the local memory of the cache node. Data can be processed without writing data from the device and accessing the storage device.

  Therefore, a high-speed response is still possible.

  In the first embodiment, in addition to these effects, there is no need for a shared memory that is accessed centrally from each node.

  For this reason, it is easy to increase the number of nodes, and it is easy to increase the scale.

  In addition, since there are few accesses to the storage device, data input / output processing is completed for a local high-speed memory, and the scale can be easily increased, the data transfer speed performance can be greatly improved.

  This embodiment will be described based on a specific example.

  FIG. 11 and FIG. 12 are diagrams schematically showing processing of one specific example of the first embodiment shown in FIG. 4, and four upper devices (higher devices 1, 2, 3, 4). Are connected to the cache nodes 2a, 2b, 2c and 2d via the mutual communication means 4. The cache nodes 2a, 2b, 2c, and 2d are connected to the storage control nodes 3a, 3b, 3c, and 3d via the mutual communication unit 4, and the storage control node is connected to a storage device such as a disk array. Hereinafter, a case where the device 3 issues an input / output request to the cache node 2b will be described.

  The node 2b receives an input / output request from the host device 3 (input / output request step in FIG. 11), and performs a cache search process. The local memory cache control information of the node 2b is searched, and it is determined whether there is a cache page corresponding to the input / output request in the cache memory of the node 2b. When there is a corresponding cache page (at the time of a cache hit), the node 2b performs a read or write process after the exclusion process, and releases the exclusion after the process.

  On the other hand, when the corresponding cache page does not exist in the local memory in the node 2b (at the time of a cache miss), the logical storage configuration table in the node 2b is referred to determine which logical storage space the input / output request corresponds to. Then, the storage control node that manages the corresponding logical storage space is requested to control the corresponding cache page (communication step B1 in FIG. 11). In this example, it is assumed that the corresponding logical storage space is found as the storage control node 3c.

  The node 3c requested to control the cache page refers to the management information table of the control right using the control right management means in the node 3c, and selects the cache node holding the control right of the corresponding cache page. Search for.

  When the node having the corresponding control right is not found, the node 3c gives the control right of the corresponding page to the node 2b, registers it in the control right management information, and notifies it (communication step B2 in FIG. 11). ').

  When the node 3c finds a cache node holding the corresponding control right, the node 3c requests the cache node for an exclusion process and a notification process (communication step B2 in FIG. 10). In this example, it is assumed that the node holding the corresponding control right is found to be the cache node 2d.

  When receiving an instruction from the node 3c, the node 2d having the control right of the cache page performs exclusive processing so that it is not operated by another processing request. Processing such as setting an exclusive flag on the management information of the corresponding page in the node 3c may be performed.

  After performing the exclusion process, the node 2d sends a notification permitting the use of the corresponding cache page and information for accessing the cache page (cache page address information) to the requesting node 2b. (Communication step B3 in FIG. 12).

  The node 2b that has received the permission accesses the cache page in the local memory of the node 2d, and if it is a read request, transfers the data of the cache page to the host device. Data is received, written to the cache page, and a request from the higher-level device 3 is processed (communication step B4 in FIG. 12).

  When the requested input / output is completed, the node 2b notifies the completion to the node 2d (communication step B5 in FIG. 12).

  The node 2d that has received the completion notification releases the exclusion for using the node 2b.

  FIG. 13 is a diagram for explaining a sequence operation when a write process is performed from the device 3 to the cache node 2b in the configuration shown in FIGS. In FIG. 13, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS. 11 and 12, respectively.

  The device 3 transmits a write request to the node 2b.

  The node 2b that has received the write request from the higher-level device 3 in step t1 searches the cache corresponding to the request, and if there is a cache page corresponding to the request, the node 2b has the right to control the cache page and is exclusive. After performing the processing, an acknowledgment (Ack) is transmitted to the higher-level device 3.

  The host device 3 that has received the affirmative response in step t2 then transmits the write data to the node 2b, and the node 2b stores the write data in the corresponding cache page. In step t3, after storing in the cache page, the request processing completion (end status) is notified, and the exclusion is released.

  FIG. 14 is a diagram showing a sequence when the control right is given to the cache node 2b. In FIG. 14, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS. 11 and 12, respectively.

  Referring to FIG. 14, the higher-level device 3 transmits a write request to the node 2b.

  In step t1, the node 2b that has received the write request from the host device 3 searches the cache corresponding to the request, and if there is no cache corresponding to the request, requests the node 3c to control the cache page corresponding to the request. To do.

  In step t2, the node 3c that has received the request from the node 2b searches for the control right holding node of the corresponding cache page, and since it is not registered, grants the right to the node 2b and notifies the right grant.

  In step t3, the node 2b that has received the right grant notification prepares a cache page, performs exclusive processing, and transmits an acknowledgment (Ack) to the higher-level device 3.

  In step t4, the host device 3 that has received the acknowledgment transmits the write data to the node 2b, and the node 2b stores the write data in the cache page. In step t5, after the cache is stored, the node 2b notifies the request processing completion (end status) and releases the exclusion.

  FIG. 15 is a diagram showing a sequence in a case where use of a cache is permitted to the node 2b from the node 2d holding the control right. In FIG. 15, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS. 11 and 12, respectively.

  The host device 3 transmits a write request to the node 2b. The node 2b that has received the write request from the higher-level device 3 in step t1 searches the cache, and when there is no corresponding cache page, requests the node 3c to control the cache page corresponding to the request.

  In step t2, the node 3c that has received the control right request from the node 2b searches for the corresponding control right holding node, and finds that the control right holding node of the corresponding cache page is the node 2d. The node 3c instructs the node 2d to use permission processing for the request from the node 2b.

  In step t3, the node 2d that received the instruction from the node 3c performs exclusive processing of the corresponding cache page, and notifies the node 2b of a use permission notification including access information necessary for the node 2b to access the cache page. .

  In step t4, the node 2b that has received the use permission notification from the node 2d transmits an affirmative response (Ack) to the write request to the higher-level device 3. In step t5, the host device 3 that has received Ack transmits write data to the node 2b. The node 2b receives the write data transmitted from the host device 3, accesses the corresponding cache page in the node 2d, and stores the write data.

  In step t6, after the data is stored in the cache page, the node 2b notifies the host device 3 of the completion of the write request processing (end status). In addition, the node 2b transmits a use completion notification to the node 2d.

  In step t7, the node 2d that has received the use completion notification from the node 2b releases the exclusion of the corresponding cache page.

  FIG. 16 is a diagram for explaining a sequence operation when a read process is performed from the higher-level device 3 to the node 2b. In FIG. 16, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS. 11 and 12, respectively.

  The host device 3 transmits a read request to the node 2b.

  In step t1, the node 2b that has received the read request from the host device 3 performs a cache search corresponding to the request. When a cache corresponding to the request is found, the corresponding cache page is excluded and the cache page data is read. In step t <b> 2, the node 2 b transmits read data to the higher-level device 3. After transmitting the end state, in step t3, the node 2b performs exclusive release of the corresponding cache page.

  FIG. 17 is a diagram showing a sequence in the case where a control right is given to the cache node 2b in response to a read request from the host device. In FIG. 17, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS. 11 and 12, respectively.

  Referring to FIG. 17, the host device 3 transmits a read request to the cache node 2b.

  In step t1, the node 2b that has received the read request from the host device 3 performs a cache search corresponding to the request, and requests the control right corresponding to the request from the node 3c when there is no corresponding cache. In step t2, the node 3c that has received the request from the node 2b searches for the corresponding control right holding node, and since it is not registered, grants the corresponding control right to the node 2b and notifies the control right grant. .

  In step t3, the node 2b that has received the notification from the node 3c prepares a cache page, performs exclusive processing, and requests the node 3c for necessary data in the storage device 8c. At step t4, the corresponding data in the storage device 8c is read by the request, and the read data is transferred from the node 3c to the node 2b via the mutual communication means and stored in the cache page of the node 2b. .

  In addition, when the node 3c receives a control right request from the node 2b in step t2 and finds that the corresponding control right holding node does not exist, the node 3c stores the data in the storage device 8c corresponding to the request in the node 3c. The process of prefetching to the local memory may be performed in parallel with the process of giving and notifying the corresponding control right to the node 2b. As a result, when the node 2b requests the corresponding data in the storage device 8c, the data read in the local memory is used to buffer the slow access speed of the storage device and store the data in the cache page. Such time can be shortened.

  When the storage of data in the cache page is completed in step t5, the node 2b transmits the data of the cache page to the higher-level device 3 and transmits end status information indicating the end of the read data. In step t6, the node 2b Release the exclusion.

  FIG. 18 is a diagram showing a sequence in the case where the node 2b is permitted to use the cache from the node 2d holding the control right. In FIG. 18, the host device 3, nodes 2b, 2d, and 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIGS.

  The host device 3 transmits a read request to the cache node 2b. In step t1, the cache node 2b that has received the read request performs a cache search, and if the corresponding cache page does not exist, requests the node 3c to control the corresponding cache page. In step t2, the node 3c that has received the request from the node 2b searches for the control right holding node of the corresponding cache page, and finds that the control right holding node of the corresponding cache page is the node 2d. The node 3c instructs the node 2d to use permission processing for the request from the node 2b.

  In step t3, the node 2d that received the instruction from the node 3c performs exclusive processing of the corresponding cache page, and notifies the node 2b of a use permission notification including access information necessary for the node 2b to access the cache page. To do.

  In step t4, the node 2b that has received the use permission notification from the node 2d accesses the corresponding cache page in the node 2d and transmits the read data to the host device 3.

  After transmitting the end status, the node 2b transmits a use completion notification to the node 2d at step t5. In step t6, the node 2d that has received the use completion notification cancels the exclusion of the corresponding cache page.

  Next, a second embodiment of the present invention will be described with reference to the drawings. As in the first embodiment, the second embodiment of the present invention has the configuration shown in FIG. 4, controls input / output with a host device such as a host computer, and temporarily stores the input / output data. Storage control nodes 3a, 3b, 3c, 3d for controlling input / output with a plurality of cache nodes 2a, 2b, 2c, 2d having a cache function and a storage device for finally recording and storing data, and a plurality of caches Nodes 2a, 2b, 2c, and 2d and intercommunication means 4 through mutual communication between the plurality of storage control nodes 3a, 3b, 3c, and 3d. The storage system 1 includes a configuration and one or more storage devices connected to each storage control node.

  In FIG. 4, for simplicity, the configuration includes four cache nodes and four storage control nodes. However, the number is not particularly limited as in the first embodiment. The intercommunication means 4 may be a bus, SCSI, LAN (Local Area Network), SAN (Storage Area Network), the Internet network, or any other suitable communication means. Further, the number of host devices and the number of storage devices are not particularly limited. The storage device may be a disk unit composed of a plurality of disk drive groups, or may be a disk array device or the like. Further, a storage device may be provided for each storage control node, and the storage control node and the storage device may be interconnected.

  In this embodiment, the control right assigned to a specific cache node is shared and managed by the storage control nodes 3a, 3b, 3c, and 3d to which cache node a certain control right is assigned.

  28, 29, and 30 are diagrams showing the configuration of storage space configuration information indicating to which storage control node the logical storage space (logical volume) recognized by the storage system 1 is allocated.

  The storage space configuration information of the second embodiment of the present invention is an example in which the specific logical storage space is divided into a predetermined size from the logical storage configuration information shown in FIG. 6 described in the first embodiment. The unit area divided into the predetermined size is called “extent”, and the unit area of the control right is allocated to the same size as the extent.

  The control right of the second embodiment of the present invention corresponds to the control right of a specific chunk described with reference to FIGS.

  In the second embodiment of the present invention, by configuring one logical volume from extents of a plurality of storage control nodes, the processing is distributed to a plurality of storage configuration nodes as compared to the first embodiment. It is possible to improve the performance by distributing the processing to the storage system of the host device. An extent usually consists of an area that is an integral multiple of a cache page and has a size of several tens to several hundreds of megabytes.

  The node having the control right can control the cache regarding the data in the extent without communicating with other nodes.

  On the other hand, if there is a cache node with control right, a cache node that does not have control right performs a predetermined operation to determine the cache of data in the extent corresponding to the node with control right. Control can be performed.

  In addition, if no control right corresponding to the extent exists in any cache node, the node that inquired the control right, that is, the node that first received the data read request or write request from the host device Is given control. This is realized by writing information indicating which cache node has the control right to the storage control node, and securing an extent in the cache node that has inquired the control right.

  After assigning control rights, if a node that receives a read or write request for data from the host device is a write after securing a cache page as necessary, the data from the host device is transferred. If the data is stored in the cache page and read, the corresponding data is stored in the cache page from the storage device via the storage control node and then transferred to the host device.

  In the example shown in FIG. 4, when the cache nodes 2a, 2b, 2c, and 2d having a cache function receive a data read request or a data write request from the host device, the local memory in the own cache node (see FIG. 5). The cache management information stored in the control memory unit is stored in the cache page storage unit in the own cache node to determine whether or not the corresponding cache page exists.

  In the second embodiment of the present invention, since the cache processing is permitted only for the extent to which the control right is given, the fact that the cache page corresponding to the specific logical address is found means that the cache page The control right is given to the extent including the logical address, and the write and read operations on the cache page can be executed without inquiring of other nodes.

  That is, when a cache node that has received a data read request or data write request from a host device determines that a corresponding cache page exists by cache search, the cache node has control over the extent that includes the cache page. If it is a data read request, the cache node has only to transfer data from the cache page to the host device, and a high-speed response to the host device is possible. If the request is a data write request, when the data is written to the cache page, the processing completion is returned to the host device, and the data is written to the storage device after the processing is completed. It becomes.

  On the other hand, in the cache node that has received the data read request or data write request from the host device, if it is determined by cache search that the corresponding cache page does not exist in the cache node, the logical storage configuration information in the cache node is displayed. If an extent including the cache page is found, a cache page is newly reserved without communicating with other nodes including the management node. If it is received and read, the corresponding data is received from the storage device via the storage control node in the cache page and then transferred to the host device.

  In either case of read request or write request, if there is a control right for the extent including the cache page, even if the cache page does not exist, the cache processing can be performed without inquiring of the management node as in the first embodiment. It is possible to increase the speed even when there is no cache page.

  When the extent including the cache page does not exist in the logical storage configuration information of the cache node, the management node that manages the control right is notified and the management node searches for the control right management information.

  At that time, if the control right holding node of the extent exists in the control management information, the cache node that accepted the request examines the management information of the cache in the control memory unit, and corresponds to the cache page storage unit in its own cache node. Search whether a cache page exists.

  As a result, if the cache page exists, if it is a data read request, the data can be transferred from the cache page of the control right holding node via the mutual communication means 4, and the data can be transferred from the storage device. A much faster response than reading is possible.

  Even if it is a data write request, when the write data from the host device is written to the corresponding cache page of the control right holding node via the mutual communication means 4, the processing is completed for the host device. Returning and writing the data to the storage device later prevents access to the storage device, so that high-speed response is possible.

  In addition, when the cache page does not exist in the node having the control right requested from the management node, a new cache page is secured, and if it is a write, the data from the host device is received from the host device. If the cache page is received via the mutual communication means 4 and the node, and if it is read, the corresponding communication data is received from the storage device via the storage control node after receiving the corresponding cache page. Then, the node that received the request from the host device transfers the request to the host device.

  FIG. 5 is a diagram showing the configuration of the cache nodes 2a, 2b, 2c, and 2d in FIG. Note that the cache nodes 2a, 2b, 2c, and 2d in FIG. Referring to FIG. 5, the cache node 2 includes a host device interface unit 10, a data processing device 11 that operates by program control and serves as a main control unit, a local memory 12, and a controller 13.

  The host device interface means 10 is connected to one or more host devices via the connection paths 5a, 5b, 5c, and 5d, receives data read requests or data write requests from the host device, and Processes data input and output with the cache node. The cache node may be provided with a plurality of higher-level device interface means, and an interconnection means such as a switch may be used for connection with the higher-level device.

  The data processing device 11 includes command control means 111, management node specifying means 112, and cache control means 113. The command control unit 111 determines each command of a data read request or a data write request from the host device received by the host device interface unit 10 and controls processing according to each command.

  The management node specifying unit 112 specifies a management node with which communication is performed when there is no extent to be read / written in the own cache node.

  The cache control unit 113 manages and controls the cache search process and the cache stored in the local memory 12.

  The local memory 12 includes a control memory unit 121 and a cache page unit 122, and is configured by a semiconductor memory that can be accessed at a higher speed than the storage device. There may be a plurality of local memories 12, and the control memory unit 121 and the cache page unit 122 may be provided in different local memories.

  The control memory unit 121 stores storage space configuration information (see FIG. 6) indicating to which storage control node the logical storage space is allocated, and control right management for determining a node to be inquired when the control right does not exist in the own node. Node information (see, for example, FIGS. 28 to 30), cache management information, and cache node control information are stored.

  The cache page unit 122 temporarily stores data input / output to / from the host device via the host device interface unit 10 in units of pages.

  The controller 13 controls data communication of the cache node 2 and also processes communication with other cache nodes and storage control nodes via the mutual communication means 4. A cache node may include a plurality of controllers.

  28, 29, and 30 are diagrams showing the configuration of storage space configuration information indicating to which storage control node the logical storage space (logical volume) recognized by the storage system 1 is allocated. In this embodiment, the extents in a certain logical volume number are managed by a table indicating which extent of which storage control node is constituted.

  The management node specifying unit 112 in FIG. 5 can determine to which storage control node the control right management information of a certain logical volume number is assigned by referring to the management node configuration information in FIG. Can be specified.

  The logical storage configuration information in FIGS. 28 to 30 is an example of the storage space configuration information shown in FIG. 6, and is an example of managing a specific logical storage space in units divided into a predetermined size. One logical volume is divided into a plurality of extents, which are named logical extents. The logical storage space under the storage control node is also divided into extent units. These extents are assigned numbers in ascending order within the logical address or logical storage space, and are named “logical extent number” and “physical extent number”, respectively.

  The logical storage configuration information in FIG. 28 is a table for associating which storage node is a physical extent with a logical extent in a logical volume. The logical extent number of a certain logical volume can be uniquely determined from the logical address that is position information indicating reading and writing in the logical volume, and the storage control node to which the logical extent is mapped in the table indicated by the logical extent number at that time Information and the number of the physical extent allocated in the storage control node are recorded.

  In the second embodiment of the present invention, whether or not a certain cache node has a control right is defined by searching the logical storage configuration information of the node and mapping the physical extent for the logical extent on the table. To do.

  If the physical extent information is mapped to the logical extent, the cache node having the logical storage configuration information has control over the extent.

  If the physical extent is not mapped to the logical extent, that is, if the storage control node and the physical extent number under the storage control node are not defined in the table determined by the logical extent number, there is no right to control the extent.

  Next, the storage control node will be described with reference to FIG. Each storage control node 3a, 3b, 3c, 3d has the same configuration. The storage control node 3 includes a storage device interface unit 20, a data processing device 21 that operates by program control and serves as a main control unit, a local memory 22, and a controller 23.

  The storage device interface unit 20 is connected to one or more storage devices via the connection paths 6a, 6b, 6c, and 6d, and inputs and outputs data between the storage device and the storage control node.

  The data processing device 21 includes a control right management unit 211 and a storage device control unit 212.

  The storage device control unit 212 controls input / output command processing to the storage device that finally records and stores data.

  The control right management unit 211 executes a processing request for the control right from the cache nodes 2a, 2b, 2c, and 2d.

  The local memory 22 includes a control memory unit 221 and is configured by a semiconductor memory that can be accessed faster than the storage device.

  The control memory unit 221 stores storage control node control information and storage system 1 device configuration information. Further, the control memory unit 221 has control right management information indicating which node has the control right for a specific cache page unit uniquely determined from the addresses in all logical storage spaces recognized by the storage system 1. Stored.

  The controller 23 controls data communication of the storage control node, is connected to the mutual communication means 4, and controls communication with other cache nodes and storage control nodes. The storage control node may include a plurality of controllers.

  31 and 32 are diagrams showing the configuration of the control right management information stored in the control memory unit 221 of the local memory 22 in FIG.

  The control right management information in FIG. 31 stored in the control memory unit 221 (see FIG. 7) includes information indicating which cache node holds the control right for an extent of a certain logical volume. A cache node number having the right to control the extent corresponds to the table.

  As a result, when a certain extent number is indicated, the control right management unit 211 checks whether the extent is in the control right management information, and determines whether there is a cache node having control right for the corresponding extent, and the control right. If there is a node that has it, the cache node can be specified. The control right management unit 211 performs processing according to this determination.

  If there is no cache node having the control right, a new control right is set, registered in the control right management information, and notified to the node that has registered the control right.

  When there is a cache node having the control right, a predetermined instruction is given to the cache node having the control right.

  Next, the operation of the second embodiment of the present invention will be described in detail.

  FIG. 33 shows that when the cache node in the second embodiment of the present invention receives a data read request or a data write request from the host device and performs a cache search in the own cache node, the cache exists in the own cache node. It is a flowchart which shows the process in case (step C1-step C18).

  Hereinafter, a case where the cache node that receives a data read request or a data write request from the host apparatus is the cache node 2a will be described as an example.

  The cache node 2a in FIG. 4 receives a data read request or data write request command from the host device via the connection path 5a by the host device interface means 10 (see FIG. 5).

  When the cache node 2a receives the command, the command control unit 111 (see FIG. 5) analyzes the request.

  Then, the cache control unit 113 (see FIG. 5) receives the analysis result of the command control unit 111, and determines whether or not the data of the logical address on the logical volume to which the requested data corresponds already exists in the cache page unit 122. The cache control information (see FIG. 23) on the control memory unit 121 (see FIG. 5) is searched and determined in the same manner as in the first embodiment (step C1 in FIG. 33).

  If the data of the corresponding logical address exists on the cache page unit 122 (see FIG. 5), the cache node 2a may perform a data read request after exclusive processing of the cache page so that it is not operated by other processing. For example, the corresponding data is immediately read from the cache page on the cache page unit 122 and transferred to the host device.

  If it is a data write request, the data sent from the host device is written to the corresponding cache page on the cache page unit 122. Since each process does not require communication with other nodes, it can be processed at high speed (step C2 in FIG. 33).

  Thereafter, the cache control unit 113 updates the cache management information of the control memory unit 121 necessary for efficient cache page management by the LRU (Least Recently Used) method and releases the exclusion.

  When the data of the logical address on the corresponding logical volume does not exist on the cache page unit 122, processing according to the procedure shown in FIG. 33 is performed.

  First, when the cache control unit 113 of the cache node 2a determines that the data at the address does not exist in the cache page, the management node specifying unit 112 of the cache node 2a determines that the extent including the logical address on the logical volume is It is determined whether or not it exists in the node (step C3 in FIG. 33). This is done using the logical storage configuration information of FIG. If the logical storage configuration information of the cache node 2a at this time is as shown in FIG. 28, the logical extent number uniquely obtained from the logical address is “2”, and the logical volume is “0”. Is as follows.

  The cache control means 113 of the cache node 2a determines one table on the logical storage configuration information from the information that the logical extent number “2” uniquely obtained from the logical address and the logical volume “0”.

  The cache control unit 113 determines whether the physical extent number and the storage control node information exist in the table corresponding to the logical extent number “2” with the logical volume “0” on the cache control information (see FIG. 28). As a result, it is understood that the extent having the physical extent number “1” of the storage control node 3a is allocated to the table having the logical extent number 2. That is, it can be determined that the cache node 2a has the right to control the extent having the logical extent number “2”.

  The cache control unit 113 of the cache node 2a newly secures a cache page (step C4 in FIG. 33) since the data having the control right related to the extent is present but the data including the corresponding logical address does not exist in the cache page portion. Then, the exclusive processing of the cache page is performed in order to continuously read or write data.

  Thereafter, if the request from the host device is a data read request, the control storage control node 3a is instructed to read the data from the storage device, is stored in the corresponding cache page of the cache node 2a, and is transferred to the host device .

  If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page, the processing completion is returned to the host device, and the data is later sent to the storage device. Write (step C5 in FIG. 33). Thus, even when the cache page of the logical address does not exist in the cache memory unit, it can be processed at high speed without communicating with the storage control node.

  Also, in step C3 in FIG. 33, when the extent including the logical address does not exist in its own node, the management node to which a request for the right to control the extent belonging to the page is to be identified is specified (step in FIG. 33). C6). The management node is specified using the management node configuration information shown in FIG.

  At this time, if the processing for the logical volume 0 and the logical storage configuration information of the cache node 2a are as shown in FIG. 28 and the logical extent number uniquely obtained from the logical address is “5”, It becomes as follows.

  The management node identification unit 112 (see FIG. 5) identifies the storage control node that manages the logical volume 0 with reference to the management node configuration information in FIG. In this case, since the storage node information (logical extent number “0”) on the table of logical volume 0 is “3a”, the node that manages the control right is the storage control node “3a”. It is found that the physical extent under the storage control node 3a is “3”.

  After specifying the corresponding management node, the controller 13 is instructed to notify, and the control right request is notified to the specified storage control node 3a via the mutual communication means 4 (step C7 in FIG. 33).

  The storage control node 3a and the controller 23 (see FIG. 7) that received the notification of the control right request receive the control right request, the control right management unit 211 determines the control right request, and the control right determination Process.

  The control right management unit 211 searches the control right management information stored in the control memory unit 221 to determine whether there is an extent of the corresponding logical address (step C8 in FIG. 33).

  In this embodiment, the control right management node (see FIG. 31) stores a control right holding node number indicating a logical extent number and a cache node having the control right of the logical extent number.

  Here, the control right request information received by the storage control node 3a is a request whose logical volume number is 0 and whose logical extent number is “5” as described above.

  Further, assuming that the control management information held by the storage control node 3a at this time has the contents shown in (FIG. 31), the control right management unit 211 holds the control in the logical extent number of the control right management information (FIG. 31). Search whether the node number is registered.

  As a result, since the control holding node number is not registered in the table having the logical extent number “5”, it can be understood that no cache node has the control right.

  As described above, when there is no control right holding node corresponding to the control right request data, the control right of the extent is newly granted to the requesting cache node 2a, and the control right management information is added. Registration is performed (step C9 in FIG. 33).

  Specifically, the node 2a is newly registered at the location of the unused control right holding node number where the logical extent number of the control right management information (see FIG. 31) of the storage control node 3a is “5”. One physical extent is secured from the physical extents under the storage control node in the storage system.

  After registering the control right, the controller 23 is instructed to notify, newly registers a physical extent via the mutual communication means 4, and notifies the cache node 2a which is the request source node that the control right has been secured. (Step C10 in FIG. 33).

  The cache node 2a that has received that a physical extent is newly assigned to the logical extent and has secured the control right registers the physical extent in the logical storage configuration information (FIG. 28), and establishes the control right.

  Specifically, when the information returned by the storage control node 3a is “9” as the physical extent number of the node 3a, the storage control node is “ This is realized by recording that “3a” and the physical extent is “9” (see FIG. 29).

  Thereafter, the cache control unit 113 secures a new cache page and performs exclusive processing of the cache page in order to read or write the logical address requested by the host device.

  Here, the cache node 2a has obtained the control right by the request from the host device, but the node voluntarily anticipates a continuous data read request without access from the host device, and the storage device previously Even in a prefetch cache operation for reading data into the cache, it is possible to obtain the same control right as in this sequence.

  Thereafter, if the request from the host device is a data read request, the control storage control node 3a is instructed to read the data from the storage device, is stored in the corresponding cache page of the cache node 2a, and is transferred to the host device .

  If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page, the completion of processing is returned to the host device, and the data is later written to the storage device ( Step C11 in FIG. 33).

  After the request processing of the host device is completed, the cache control unit 113 of the cache node 2a updates the cache management information of the control memory unit 121 necessary for efficient cache page management by the LRU method and releases the exclusion. To do.

  In the processing for this write request, access to the storage device does not occur until a response is returned to the host device, so a high-speed response is possible.

  In step C8 of FIG. 33, when the control right management information is searched and the physical extent of the corresponding logical address is registered and there is a control right holding node, the storage control node 3a sends the control right holding node to the control right holding node. A request to use the corresponding physical extent of the cache node 2a which is the request source node is instructed (step C12 in FIG. 33).

  In the following description, it is assumed that the control right holding node is the cache node 2b based on the control right management information.

  It is assumed that the logical extent number received by the storage control node 3a is “6” and the control management information is shown in FIG.

  The control right management unit 211 of the storage control node 3a searches whether the control right holding node number is registered in the table whose logical extent number is 6 in the control right management information (FIG. 31).

  As a result, the control right holding node number “2b” is registered at the position where the physical extent number is “6”, and the extent whose logical extent number is “6” with the logical volume “0” is controlled by the cache node 2b. I understand that I have the right.

  Thereafter, the control right management unit 211 of the storage control node 3 a instructs the controller 23 to notify, and notifies the cache node 2 b of the use request of the corresponding logical extent via the mutual communication unit 4.

  The cache node 2b, which is the control right holding node of the corresponding logical extent, receives the logical address for reading and writing the use request of the corresponding logical extent of the cache node 2a from the storage control node 3a by the controller 13 of the cache node 2b. Then, the cache control unit 113 of the cache node 2b performs exclusive processing so that the corresponding logical extent is not manipulated by other processing (step C13 in FIG. 33).

  The cache control unit 113 of the cache node 2b searches after the exclusive processing of the corresponding logical extent whether the data corresponding to the logical address in the corresponding logical extent exists in the cache page portion of the cache node 2b (FIG. 33). Step C14).

  As a result, if a cache page corresponding to the data of the corresponding logical address exists in the cache page, the cache page is excluded so as not to be manipulated by other processing, and address information for accessing the cache page is stored in the cache page. The controller 13 of the node 2b is instructed to notify the cache node 2a, which is the control right requesting node, and notifies via the mutual communication means 4 (step C15 in FIG. 33).

  The cache node 2a that has received the notification of the address information for accessing the corresponding cache page thereafter transmits the data stored in the corresponding cache page of the cache node 2b to the upper level if the request from the higher-level device is a data read request. Transfer to device.

  If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page of the cache node 2b, the processing completion is returned to the host device, and the data is later stored in the storage device. (Step C16 in FIG. 33).

  In this process for the control right holding node, a high-speed response is possible because an access to the storage apparatus that requires a data response time does not occur until a response is returned to the host apparatus.

  Also, in step C14 of FIG. 33, if the cache page corresponding to the data of the corresponding logical address does not exist in the cache page, the cache control unit 113 of the cache node 2b newly secures the cache page and continues to execute it. In order to read or write data, exclusive processing of the cache page is performed (step C17 in FIG. 33).

  At this time, if the logical extent number with the logical volume number 0 is “6” and the logical storage configuration information of the cache node 2b is as shown in FIG. 30, the cache control means 113 of the cache node 2b If the request from the host device received by the cache node 2a is a data read request, or if the request from the host device is a data read request, the cache control means 113 of the cache node 2b uses logical storage control information (see FIG. 30) and refer to the table whose logical extent number is “6”.

  As a result, since the logical extent number 6 is associated with the location where the physical extent number of the storage control node 3b is “10”, the cache control means 113 (FIG. 5) of the cache node 2b notifies the controller 13. And instructing the storage control node 3b via the mutual communication means 4 to read the data on the physical extent.

  The storage control node 3b that has received the notification of the control right request receives the control right request at the controller 23 (see FIG. 7), reads the data whose subordinate physical extent number is 10, and makes the mutual communication means 4 Through the cache page on the cache node 2b.

  Thereafter, the cache node 2b transfers the data on the cache page via the mutual communication means 4 to the host device via the cache node 2a.

  If the request from the higher-level device is a data write request, the cache control unit 113 of the cache node 2b instructs the controller 13 to issue a write notification for the newly secured cache page, and causes the mutual communication unit 4 to To the cache node 2b.

  The cache node 2a writes the write data received from the host device to the corresponding cache page of the cache node 2b via the communication unit 4 in accordance with the notification content (write address or the like) from the cache node 2b, and then the host device Then, the processing end notification is released, and thereafter, the exclusive processing of the corresponding cache page and logical extent is released (step C18 in FIG. 33).

  Thereafter, the cache node 2b refers to the logical storage control information (see FIG. 30) and refers to the table having the logical extent number 6.

  As a result, since the logical extent number 6 is associated with the location where the physical extent number of the storage control node 3b is “10”, the data of the logical extent number 6 is stored in the logical address corresponding to the physical extent number of the cache node 2b “10”. Write.

  Next, a third embodiment of the present invention will be described. The configuration of the third embodiment of the present invention is the same as that of the first and second embodiments of the present invention shown in FIG. 4, and cache nodes 2a, 2b, 2c and 2d, and storage control nodes 3a and 3b. 3c, 3d, and mutual communication means 4.

  Referring to FIG. 19, each cache node 2 in the third embodiment of the present invention includes higher-level device interface means 10, a local memory 12, and a controller 13, as in the first embodiment of the present invention. .

  Referring to FIG. 20, each storage control node 3 in the third embodiment of the present invention is similar to the first embodiment of the present invention in that the storage device interface means 20, the local memory 22, and the controller 23 are used. With.

  In the third embodiment of the present invention, the controller 13 includes a microcomputer and a program ROM (Read Only Memory) and can perform processing in parallel. The controller 13 is connected to the host device interface means 10 and the local memory 12 and to the mutual communication means 4.

  For this reason, the controller 13 can access the local memory 12 at a high speed and can also access other nodes via the mutual communication means 4.

  The cache node control program 131 is stored in the program ROM of the controller 13 and is read into the microcomputer of the controller 13 to control the operation of the controller 13. The control memory unit 121 and the cache page unit are stored in the local memory 12. 122 is generated.

  The controller 13 executes the same processing as the processing by the data processing apparatus 11 in the first embodiment under the control of the cache node control program 131.

  Similarly, the controller 23 has a built-in microcomputer and program ROM and can perform processing in parallel. The controller 23 is connected to the storage device interface means 20 and the local memory 22 and to the mutual communication means 4. .

  For this reason, the controller 23 can access the local memory 22 at high speed and can also access other nodes via the mutual communication means 4.

  The storage control node control program 231 is stored in the program ROM of the controller 23 and is read into the microcomputer of the controller 23 to control the operation of the controller 23 and the local memory 22 includes control right management information. A memory unit 221 is generated. The controller 23 executes the same processing as the processing by the data processing device 21 in the first embodiment under the control of the control program 231 of the storage control node.

  Still another embodiment of the present invention will be described. FIG. 21 is a diagram showing the configuration of the fourth exemplary embodiment of the present invention. In this embodiment, the cache node 2 and the storage control node 3 of the first embodiment are configured by a single node 9, and each of the nodes 9a, 9b, 9c, 9d is a LAN, a SAN, or the like. An arbitrary communication means 5 is connected to the host devices 7a, 7b, 7c and 7d, is connected to the storage devices 8a, 8b, 8c and 8d, and is connected to other nodes via the mutual communication means 4. There are no particular restrictions on the number of nodes, host devices, and storage devices.

  FIG. 22 is a diagram showing the configuration of the node 9 of the fourth embodiment shown in FIG. Referring to FIG. 22, the node 9 includes input / output interface means 90, a data processing device 91, a local memory 92, and a controller 93.

  The data processing device 91 includes the command control unit 111, the control right management node specifying unit 112, the cache control unit 113, the control right management unit 211, and the storage device control unit 212 shown in FIGS. I have.

  The command control unit 111 determines each command of a data read request or a data write request from the host device received by the input / output interface unit 90, and controls processing according to each command.

  The management node specifying unit 112 specifies a node that manages a control right to be communicated when a cache miss occurs in the own cache node.

  The cache control unit 113 manages and controls the cache search process and the cache stored in the local memory 92.

  The local memory 92 includes a control memory unit 121 including control right management information and a cache page unit 122, and is configured by a semiconductor memory that can be accessed at higher speed than the storage device (8a and 8b in FIG. 21).

  The control memory unit 121 stores storage space configuration information (see FIG. 6) indicating to which storage control node a logical storage space is allocated, cache management information, and cache node control information. The cache page unit 122 temporarily stores data input / output to / from the host device via the input / output interface unit 90 in units of pages.

  The controller 93 controls data communication of the node 9 and also processes communication with other nodes via the mutual communication means 4.

  The control right management unit 211 executes a processing request for the control right from the nodes 9a, 9b, 9c, 9d (see FIG. 21).

  The storage device control unit 212 controls input / output command processing to the storage unit. The control right management information included in the control memory unit 121 indicates which node has the control right for each cache page unit uniquely determined from addresses in all logical storage spaces recognized by the storage system. Note that the operation of this embodiment follows the flowchart shown in FIG. 10 described in the first and second embodiments, so that the description thereof is omitted.

  Still another embodiment of the present invention will be described. In the fifth embodiment of the present invention, the host device 3 issues a read request to the cache node 2b, and the cache node 2b does not have the control right of the cache page related to the data of the logical address indicated by the request. The processing in the case of 2d is different from the first embodiment and the second embodiment. In the following, the fifth embodiment of the present invention will be described mainly with respect to the differences from the first embodiment and the second embodiment, and the description of the same process will avoid duplication. Omitted where appropriate.

  FIG. 34 is a diagram showing a sequence when the cache node 2b that requested the cache page is permitted to use the cache page from the cache node 2d that holds the control right. In FIG. 34, the host device 3, cache nodes 2b, 2d, and storage control node 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIG. 4, respectively.

  Hereinafter, a case where a read request is received from a higher-level device will be specifically described with reference to FIG. In the case of the present embodiment, the write request from the host device performs the same processing as in the first embodiment and the second embodiment.

  First, a specific example corresponding to the processing of the first embodiment will be described below. When the cache node 2b receives a read request from the host device 3, the cache node 2b searches whether the data specified by the read request exists in the cache page portion of the cache node 2b. In this embodiment, the control right is held in the cache node 2d. Therefore, even if the search is performed, the control right is not found, and an inquiry about the control right of the cache page is notified to the storage control node 3c (step s1).

  The storage control node 3c that has received the notification of necessity searches the control right holding node of the cache page. In this embodiment, since the control right is held in the cache node 2d, as a result of the search, the control right holding node becomes the cache node 2d. The storage control node 3c notifies the cache node 2d of the use of the cache page using the mutual communication means 4 (step s2).

  Upon receiving the notification, the cache node 2d performs an exclusive process on the cache page, and transmits the data of the cache page to the cache node 2b to the cache node 2b using the mutual communication unit 4 ( Step s3).

  The cache node 2b receives the data from the cache node 2d, and subsequently transmits the data to the host device 3 (step s4).

  Then, after transmitting the end status to the host device 3, the cache node 2b transmits a use completion notification to the cache node 2d using the mutual communication means 4 (step s5), and the cache node 2d determines that the cache page is exclusive. Release (step s6).

  Similarly, in this embodiment, a specific example corresponding to the processing of the second embodiment will be described with reference to FIG. The configuration and the like are the same as described above.

  First, when the cache node 2b receives a read request from the host device 3, the cache node 2b searches whether the data specified by the read request exists in the cache page portion of the cache node 2b. In this embodiment, the control right is held in the cache node 2d, and therefore cannot be found in the search. Subsequently, the cache node 2b is searched for an extent containing the data. In this embodiment, since the cache node 2d has the control right, no search for the extent is found, and the storage control node 3c is notified of a request to use the control right of the extent (step s1).

  Receiving the notification, the storage control node 3c searches for the control right holding node of the extent. In this embodiment, since the control right holding node is the cache node 2d, the storage control node 3c notifies the usage request for the extent to the cache node 2d using the mutual communication means 4 (step s2).

  When the cache node 2d receives the use request for the extent, the cache node 2d performs exclusive processing of the extent, and then searches for whether or not the data that has received the read request from the higher-level device 3 exists in the cache page portion of the cache node 2d. Is performed (step s3).

  If the corresponding cache page does not exist for the extent search described above, the cache control unit 113 of the cache node 2d newly secures the cache page, and the cache page is used for continuous data reading. Perform exclusive processing. The cache control unit 113 of the cache node 2d instructs the controller 13 to notify, and notifies the storage control node 3c of a data read request via the mutual communication unit 4.

  Receiving the request notification, the storage control node 3c reads the corresponding data and stores it in the cache page on the cache node 2d via the mutual communication means 4 (step s8).

  Thereafter, the cache node 2d transfers the data on the cache page via the mutual communication means 4 to the upper level device via the cache node 2b (step s5).

  If there is a corresponding cache page for the search for the cache page part in step s3, the data in the cache page in which the data is stored is transferred to the cache node 2b using the mutual communication means 4. The data is transferred to the host device via 2b (step s4).

  In step s3 in FIG. 35, if the transfer of data to the higher-level device is completed regardless of whether or not the corresponding data cache page exists in the cache node 2d, the cache node 2b determines the end status for the higher-level device 3. Transmit (step s6).

  Thereafter, the use completion notification of the control right is transmitted to the cache node 2d using the mutual communication means 4, and the cache node 2d releases the exclusion of the cache page and the exclusion of the extent (step s7).

  In either case, in step t3 (see FIG. 18) of the first and second embodiments, the cache node 2d sends data instead of the cache page use permission notification, thereby The number of steps can be reduced, and the speed can be further increased as compared with the first and second embodiments.

  Still another embodiment of the present invention will be described. In the sixth embodiment of the present invention, the host device 3 issues a write or read request to the cache node 2b, and the cache node 2d does not have control over the data at the logical address indicated by the request. The processing in the case of having is different from the first embodiment and the second embodiment. In the following, the sixth embodiment of the present invention will be described mainly with respect to the differences from the first embodiment and the second embodiment, and the description of the same process will avoid duplication. Omitted where appropriate.

  36, 37, and 38, the host device 3, cache nodes 2b, 2d, and storage control node 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIG. 4, respectively.

  Hereinafter, in the present embodiment, a case where a write request is received from the host apparatus 3 (processing corresponding to the first embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a write request from the higher-level device 3, a search is performed to determine whether the data specified by the write request exists in the cache page portion of the cache node 2b. Since the node 2d has the control right, the storage control node 3c is requested next for the control right of the cache page (step s1). The storage control node 3c searches for the control right holding node of the cache page and finds that the control right holding node is the cache node 2d.

  The storage control node 3c notifies the cache node 2b that the control right is in the cache node 2d using the mutual communication means 4 (step s2).

  The cache node 2b makes a use request for the cache page to the cache node 2d using the mutual communication unit 4 (step s3).

  The cache node 2d performs exclusive processing of the corresponding cache page, and notifies the cache node 2b of a use permission notification including access information (address, etc.) of the corresponding cache page on the cache node 2d (step s4).

  The cache node 2b transmits an affirmative response (Ack) to the write request to the higher-level device 3 (step s5).

  The host device 3 that has received the affirmative response (Ack) transmits the write data to the cache node 2b (step s6).

  The cache node 2b receives the write data transmitted from the host device 3, accesses the corresponding cache page in the cache node 2d, stores the write data, and after storing the data in the cache page, the cache node 2b The write request end status is transmitted to the host device 3 (step s7).

  Thereafter, the use completion notification of the corresponding cache page is transmitted to the cache node 2d. Thereafter, the cache node 2d that has received the use completion notification from the cache node 2b releases the exclusion of the corresponding cache page and completes the processing (step s8).

  Next, in the present embodiment, a case where a read request is received from the host apparatus 3 (processing corresponding to the first embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a read request from the host device 3, the cache node 2b searches whether the data specified by the read request exists in the cache page portion of the cache node 2b. Since the node 2d has the control right, it cannot be found even if it is searched. Next, the control right for the cache page is requested to the storage control node 3c (step s1).

  The storage control node 3c searches for a control right holding node of the cache page. In this embodiment, since the control right holding node is the cache node 2d, the storage control node 3c uses the mutual communication means 4 to notify the cache node 2b that the control right is in the cache node 2d. (Step s2).

  The cache node 2b makes a use request for the cache page to the cache node 2d using the mutual communication unit 4 (step s3).

  The cache node 2d that has received the use request performs exclusive processing of the corresponding cache page, and notifies the cache node 2b of a use permission notification including access information (address, etc.) of the corresponding cache page on the cache node 2d (step s4). ).

  In response to the notification from the cache node 2d, the cache node 2b accesses the corresponding cache page in the cache node 2d and transmits the read data to the higher-level device 3 (step s5).

  Next, the cache node 2b transmits a completion status of the reading process to the host device, and then transmits a use completion notification to the cache node 2d (step s6).

  The cache node 2d that has received the notification cancels the exclusion of the corresponding cache page, and the processing is completed (step s7).

  In the present embodiment, a case where a write request is received from the host apparatus 3 (a process corresponding to the second embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a write request from the host device 3, the cache node 2b searches whether the data specified by the write request exists in the cache page portion of the cache node 2b. In the example, when the cache node 2d has the control right, the search result is not found, and it is continuously searched whether the extent including the data exists in the cache node 2b. In this embodiment, since the cache node 2b does not have the control right, the search for this extent is not found, and next, the storage control node 3c is requested to use the control right for the extent (step s1). .

  The storage control node 3c searches for the control right holding node of the extent. In this embodiment, since the control right holding node is the cache node 2d, the storage control node 3c determines that the control right for the extent exists in the cache node 2d with respect to the cache node 2b. (Step s2).

  Next, the cache node 2b makes a use request for the extent to the cache node 2d using the mutual communication unit 4 (step s3). When the cache node 2d receives the use request for the extent, the cache node 2d performs exclusive processing of the extent, and then searches for whether or not the data for which the write request has been received from the host device 3 exists in the cache page portion of the cache node 2d. I do.

  When the corresponding cache page does not exist for the above-described extent search, the cache control unit 113 of the cache node 2d newly secures the cache page and performs data writing to be performed continuously. After performing the exclusive processing of the cache page, the cache node 2b is notified of a use permission notification including access information (address, etc.) of the cache page. If there is a corresponding cache page for the search for the cache page portion, similarly, the cache node 2d notifies the cache node 2b of a usage permission notification including access information (address, etc.) of the cache page (step s4). ).

  In step s4, in any case where the corresponding data cache page exists or does not exist in the cache node 2d, when the cache node 2b receives the cache page usage permission notification from the cache node 2d, the cache node 2b A positive response (Ack) to the write request is transmitted to the host device 3 (step s5). The host device 3 that has received Ack transmits write data to the cache node 2b. The cache node 2b receives the write data transmitted from the host device 3, accesses the corresponding cache page in the cache node 2d, and writes the data.

  If the data from the host device is stored in the cache page, the cache node 2b transmits an end status (step s7). Thereafter, the use completion notice of the control right is transmitted to the cache node 2d using the mutual communication means 4, and the cache node 2d releases the exclusion of the cache page and the exclusion of the extent (step s8).

  Next, in the present embodiment, a case where a read request is received from the host device 3 (processing corresponding to the second embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a read request from the host device 3, the cache node 2b searches whether the data specified by the read request exists in the cache page portion of the cache node 2b. In this embodiment, when the control right is the cache node 2d, the search result is not found, and it is continuously searched whether the extent including the data exists in the cache node 2b. In this embodiment, since the cache node 2b does not have the control right, the search for this extent is not found, and next, a request for using the control right of the extent is requested to the storage control node 3c (step s1). ).

  The storage control node 3c searches for the control right holding node of the extent. In this embodiment, since the control right holding node is the cache node 2d, the storage control node 3c indicates that the control right of the extent exists in the cache node 2d with respect to the cache node 2b. (Step s2).

  Next, the cache node 2b makes a use request for the extent to the cache node 2d using the mutual communication unit 4 (step s3).

  When the cache node 2d receives the use request for the extent, the cache node 2d performs exclusive processing of the extent, and then searches for whether or not the data that has received the read request from the higher-level device 3 exists in the cache page portion of the cache node 2d. (Step s4).

  When the corresponding cache page does not exist for the above-described extent search, the cache control unit 113 of the cache node 2d newly secures the cache page and performs the data reading to be performed continuously. Exclusive processing of the cache page is performed. Similarly to the second embodiment, the cache control unit 113 of the cache node 2d determines the storage control node of the extent by searching the control right management information (FIG. 8).

  As a result, assuming that the extent read destination is under the storage control node 3c, the cache control unit 113 instructs the controller 13 to notify the storage control node 3c via the mutual communication unit 4. Notify the data read request.

  Receiving the request notification, the storage control node 3c reads the corresponding data and stores it in the cache page on the cache node 2d via the mutual communication means 4 (step s9).

  If there is a corresponding cache page for the search for the cache page portion in step s4, the cache page storing the data is excluded, and there is no corresponding cache page for the search for the cache page portion. When data is read from the storage control node 3c, exclusive control of the cache page of the data is performed, and a usage permission notification including access information (address, etc.) of any cache page is sent to the cache node 2b depending on the condition. Notification is made (step s5).

  In response to the usage permission notification from the cache node 2d, the cache node 2b accesses the corresponding cache page in the cache node 2d and transmits the read data to the higher-level device 3 (step s6).

  When the transfer of data to the higher level apparatus 3 is completed, the cache node 2b transmits an end status to the higher level apparatus 3, and transmits a control right use completion notification to the cache node 2d using the mutual communication means 4 ( Step s7).

  The cache node 2d that has received the notification from the cache node 2b releases the exclusion of the cache page and the exclusion of the extent, and the processing is completed (step s8).

  In any case, when a control right inquiry is made, a node (storage control node 3c in this embodiment) that manages the control right for the inquired node (cache node 2b in this embodiment) The node that has inquired the control right always returns the control right to the node that has inquired the control right by returning information indicating which node has the control right. Information can be obtained from the node that manages the above.

  In the first embodiment and the second embodiment, when a failure such as a communication failure between nodes occurs, this is performed by the node having the control right after processing the control right inquiry. The process to be performed must be redone, and the process may take time.

  The processing at the time of a failure in this embodiment is a relatively simple process of having / not having the control right and which node has the control right, so that the process for recovery is simple and short. Can be done.

  Still another embodiment of the present invention will be described. In the seventh embodiment of the present invention, the host device 3 issues a write request to the cache node 2b, and the cache node 2d does not have the control right for the data of the logical address indicated by the request but in the cache node 2b. The processing in this case is different from that in the sixth embodiment. In the present embodiment, the processing for the read request from the host device 3 is the same as that in the sixth embodiment. Other processes are the same as those in the first embodiment or the second embodiment. Hereinafter, the seventh embodiment of the present invention will be described by referring to differences from the sixth embodiment.

  In FIG. 39, the host device 3, cache nodes 2b, 2d, and storage control node 3c correspond to the host device 3, cache nodes 2b, 2d, and storage control node 3c in FIG. 4, respectively.

  Next, in the present embodiment, a case where a write request is received from the host apparatus 3 (processing corresponding to the first embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a write request from the host device 3, the cache node 2b searches for the data specified by the write request in the cache page portion of the cache node 2b. Since this is a condition that does not, the storage control node 3c is requested to control the cache page (step s1).

  The storage control node 3c searches for a control right holding node of the cache page. In this embodiment, since the control right holding node is the cache node 2d, the storage control node 3c uses the mutual communication means 4 to notify the cache node 2b that the control right is in the cache node 2d. (Step s2).

  Thereafter, the cache node 2b transmits an acknowledgment (Ack) to the write request to the higher-level device 3 (step s3).

  The host device 3 that has received the positive response (Ack) transmits the write data to the cache node 2b. The cache node 2b receives the write data transmitted from the host device 3, and transmits the cache page use request and the write data to the cache node 2d (step s4).

  When the cache node 2d receives the cache page use request and data, the cache node 2d stores the write data in an area for temporarily storing the data. This temporary area is used for an unused (empty) cache page in the cache page unit 122. The cache control unit 113 of the cache node 2d searches for a cache page corresponding to the data indicated by the logical address received from the higher-level device 3, and performs exclusion processing on the cache page found as a result of the search. After that, the cache node 2d writes the data in the temporary area to the cache page found by the search, then releases the used temporary area, and informs the cache node 2b that the writing process to the cache page has ended. (Step s5).

  When the cache node 2b receives a notification from the cache node 2d indicating that the writing to the cache page has been completed, the cache node 2b transmits a write request completion status to the host device 3, and transmits a use completion notification to the cache node 2d ( Step s6).

  Thereafter, the cache node 2d that has received the use completion notification from the cache node 2b cancels the exclusion of the corresponding cache page and completes the processing (step s7).

  Next, in this embodiment, a case where a write request is received from the host apparatus 3 (a process corresponding to the second embodiment) will be specifically described with reference to FIG.

  First, when the cache node 2b receives a write request from the host device 3, the cache node 2b searches whether the data specified by the write request exists in the cache page portion of the cache node 2b. Since the condition does not exist in the example, the cache node 2b is continuously searched for an extent including the data. In this embodiment, since the cache node 2b does not have the control right, the search for this extent is not found, and next, the storage control node 3c is requested to use the control right for the extent (step s1). .

  The storage control node 3c searches for the control right holding node of the extent and finds that the control right holding node is the cache node 2d. The storage control node 3c notifies the cache node 2b that the right to control the extent exists in the cache node 2d using the mutual communication means 4 (step s2).

  Thereafter, the cache node 2b transmits an acknowledgment (Ack) to the write request to the higher-level device 3 (step s3).

  The host device 3 that has received the affirmative response (Ack) transmits the write data to the cache node 2b (step s4).

  The cache node 2b receives the write data transmitted from the host device 3, and transmits the extent use request and the write data to the cache node 2d.

  The cache node 2d that has received the use request and data stores the received write data in an area for temporarily storing the data. This temporary area is used for an unused (empty) cache page in the cache page unit 122. The cache control unit 113 of the cache node 2d performs the exclusive processing of the extent, and then searches whether or not the data that has received the write request from the higher-level device 3 exists in the cache page portion of the cache node 2d. If there is no corresponding cache page for the cache page search described above, the cache control unit 113 of the cache node 2d is not operated by other processing on the cache page in which data is written as a temporary area. After the exclusion process is performed as described above, the cache control information is added to the cache control information in the same procedure as the newly secured cache page described in the second embodiment as a formal cache page.

  If there is a cache page corresponding to the search for the cache page portion, the cache node 2d writes the temporary area data to the cache page found by the search and then releases the used temporary area.

  In any case where the corresponding data cache page exists or does not exist in the cache node 2d, when the cache node 2d finishes the process for the cache page, the cache node 2b is notified that the write process for the cache page is finished. (Step s5).

  Upon receipt of the write processing end notification from the cache node 2d, the cache node 2b transmits the write processing end status to the host device 3, and later uses the mutual communication means 4 to notify the use completion notification of the control right. It transmits to the node 2d (step s6).

  Thereafter, the cache node 2d releases the exclusion of the cache page and the exclusion of the extent (step s7).

  According to the present embodiment, in any case, notification of an acknowledgment (Ack) to the higher-level device 3 performed in step t4 (see FIG. 15) in the first embodiment and the second embodiment is performed. It is possible to return it at the stage of step s3 in FIG. 39, and the overall processing time can be shortened.

As yet another embodiment of the present invention,
Regarding the read request from the host device 3, the processing of the fifth embodiment is performed,
The processing of the seventh embodiment is performed with respect to the write request from the host device 3.
It is supposed to be configured. In either case of read / write requests, the processing time is shortened.

The present invention
A disk array device composed of a plurality of nodes having cache means and usable as a single storage system;
A cache control device that is composed of a plurality of nodes having cache means and can be used as a single cache system;
A switch device composed of a plurality of switches having cache means and usable as a single storage system;
It can also be applied.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the configuration of the above embodiment, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, modifications are included.

It is a figure for demonstrating the principle of the cache control of this invention. It is a figure for demonstrating the principle of the cache control of this invention. It is a flowchart for demonstrating the cache control procedure of this invention. It is a figure which shows the structure of one Example of this invention. It is a figure which shows the structure of the cache node of one Example of this invention. It is a figure which shows the structure of the storage space structure information of one Example of this invention. It is a figure which shows the structure of the storage control node of one Example of this invention. It is a block diagram of the control right management information in the control right management means of one Example of this invention. It is a block diagram of the control right management information in the control right management means of one Example of this invention. 6 is a flowchart illustrating an example of an operation when a cache node receives a data request from a higher-level device in an embodiment of the present invention. It is a figure for demonstrating the operation | movement procedure of one Example of this invention. It is a figure for demonstrating the operation | movement procedure of one Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of one Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of one Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of one Example of this invention. It is a sequence diagram for demonstrating the read-out procedure of one Example of this invention. It is a sequence diagram for demonstrating the read-out procedure of one Example of this invention. It is a sequence diagram for demonstrating the read-out procedure of one Example of this invention. It is a figure which shows the structure of the cache node in the 3rd Example of this invention. It is a figure which shows the structure of the storage control node in 3rd Example of this invention. It is a figure which shows the structure of the 4th Example of this invention. It is a figure which shows the structure of the node of the 4th Example of this invention. It is a figure which shows the structure of the cache control information of 1st Example of this invention. It is a figure which shows the structure of the page tag of 1st Example of this invention. It is a figure which shows the structure of the cache control information of 1st Example of this invention. It is a figure which shows the structure of the cache control information of 1st Example of this invention. It is a figure which shows the structure of the cache control information of 1st Example of this invention. It is a figure which shows the structure of the logical storage structure information of 2nd Example of this invention. It is a figure which shows the structure of the logical storage structure information of 2nd Example of this invention. It is a figure which shows the structure of the logical storage structure information of 2nd Example of this invention. It is a figure which shows the structure of the control management information of 2nd Example of this invention. It is a figure which shows the structure of the management node structure information of 2nd Example of this invention. 11 is a flowchart illustrating an example of an operation when a cache node receives a data request from a higher-level device in the second exemplary embodiment of the present invention. It is a sequence diagram for demonstrating the read-out procedure of the 5th Example of this invention. It is a sequence diagram for demonstrating the read-out procedure of the 5th Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of the 6th Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of the 6th Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of the 6th Example of this invention. It is a sequence diagram for demonstrating the write-in procedure of the 7th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Storage system 2, 2a, 2b, 2c, 2d Cache node 3, 3a, 3b, 3c, 3d Storage control node 4 Intercommunication means 5a, 5b, 5c, 5d Host apparatus connection path 6a, 6b, 6c, 6d Storage apparatus Connection path 7a, 7b, 7c, 7d Host device 8a, 8b, 8c, 8d Storage device 9, 9a, 9b, 9c, 9d Node 10 Host device interface means 11 Data processing device 111 Command control means 112 Management node specifying means 113 Cache Control unit 12 Local memory 121 Control memory unit 122 Cache page unit 13 Controller 131 Cache node control program 20 Storage device interface unit 21, 91 Data processing unit 211 Control right management unit 212 Storage device control unit 22, 9 2 Local memory 221 Control memory unit 222 Control right management information 23, 93 Controller 30 Hash table 31 Page tag 40 Address information 41 Page address 42 Pointer 90 Input / output interface means 231 Storage control node control program A1 Management node specifying step A2 Control right Request step A3 Control right determination processing step A4 Control right registration step A5 Control right registration notification step A6 Cache page exclusion processing step A7 Cache page usage request step A8 Cache page exclusion processing step A9 Cache page usage notification step

Claims (87)

A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
When the first processing unit does not have the control right for the corresponding unit area, the first processing unit identifies the corresponding unit area or predetermined data in the unit area to the management processing unit. Means for transmitting a first signal containing information,
The management processing unit
Receiving the first signal from the first processing unit and referring to a storage unit that stores and manages which processing unit currently has the control right of the unit area, searches for the processing unit having the control right Means to
As a result of the search, if there is a second processing unit having a control right for the corresponding unit region, the corresponding unit region or data in the unit region is identified with respect to the second processing unit. Means for transmitting a second signal containing information;
With
The second processing unit receives the second signal from the management processing unit, and accesses the first processing unit to access a cache area of a cache memory corresponding to data in the corresponding unit area. A means of giving information,
The cache control system, wherein the first processing unit accesses a processing target cache area based on information given from the second processing unit.   The second processing unit having the control right receives a signal from the management processing unit, permits only the first processing unit to update the predetermined data in the unit area, and other processing units The cache control system according to claim 1, further comprising means for keeping the update from being permitted.   The management processing unit includes means for granting the control right to the first processing unit that has requested the control right when there is no processing unit having the control right regarding the unit area as a result of the search. The cache control system according to claim 1, wherein: The plurality of processing units are provided in a plurality of nodes connected to each other via communication means,
The cache control system according to claim 1, wherein a cache memory for temporarily storing data in the unit area is provided in one or more nodes. The plurality of processing units are provided in a plurality of nodes connected to each other via communication means,
The cache control system according to claim 1, wherein the cache memory is stored in a shared memory shared by the plurality of nodes.   The said 1st process part identifies the said management process part with reference to the structure information which memorize | stored the correspondence with the said unit area | region and the process part of the said unit area, The said process part is characterized by the above-mentioned. Cache control system.   The cache control system according to claim 1, wherein the first processing unit includes a unit that determines whether or not the first processing unit has the right to control the unit area.   The management processing unit searches the control information storing the correspondence between the unit area and the processing unit having the control right of the unit area, and specifies the second processing unit having the control right of the unit area The cache control system according to claim 1, wherein:   The first processing unit sets the unit area as a page unit of the cache, and performs a hit check of the cache from information for identifying data requested by the upper processing means, thereby giving the right to control the unit area. 2. The cache control system according to claim 1, further comprising means for determining whether or not the first processing unit has. A method of performing cache control of at least one cache memory by a plurality of processing units,
When the first processing unit does not have a control right for a unit area uniquely determined from an address of predetermined data in the address space to be cached, the first processing unit determines which of the plurality of processing units For a processing unit that manages whether the processing unit has control over the unit area (referred to as a “management processing unit”), information that identifies the corresponding unit area or predetermined data in the corresponding unit area Transmitting a single signal;
The management processing unit receives the first signal from the first processing unit, refers to a storage unit that stores and manages which processing unit currently has the control right for the unit area, and controls the control right. Searching for a processing unit having
When there is a second processing unit having a control right for the corresponding unit area, the second processing unit includes information for identifying the corresponding unit area or predetermined data in the unit area. Transmitting a second signal;
The second processing unit receives the second signal from the management processing unit, and information for accessing the first processing unit to a cache area corresponding to predetermined data in the corresponding unit area A process of providing
The first processing unit is configured to access a cache area to be processed based on the information given by the second processing unit;
A cache control method comprising:   The second processing unit having the control right receives the instruction from the management processing unit and permits the first processing unit to access the cache area corresponding to the predetermined data in the unit area. 11. The cache control method according to claim 10, further comprising:   If there is no second processing unit having the right to control the unit area as a result of the search, the management processing unit controls the unit area to the first processing unit that has requested the control right. The cache control method according to claim 10, further comprising a step of granting a right.   The cache control method according to claim 10, wherein the first processing unit specifies the management processing unit with reference to configuration information in which a correspondence between the unit area and the unit area is stored. .   The management processing unit searches the control information storing the correspondence between the unit area and the processing unit having the control right of the unit area, and specifies the second processing unit having the control right of the unit area The cache control method according to claim 10, wherein:   11. The cache according to claim 10, wherein after the access to the cache area corresponding to the predetermined data in the unit area ends, the first processing unit of the request source notifies the use completion of the cache area. Control method.   The second processing unit having the control right receives a notification of completion of use of the cache area from the first processing unit, and cancels the permission of the cache area access of the first processing unit. The cache control method according to claim 10.   The cache control method according to claim 10, wherein the first processing unit includes a step of determining whether or not the first processing unit has the right to control the unit area.   The first processing unit uses the unit area as a page unit of the cache, and performs a cache hit check from information for identifying data requested by the higher-level processing means, thereby granting the right to control the unit area. The cache control method according to claim 10, further comprising a step of determining whether or not the processing unit has one processing unit. A plurality of cache nodes having a cache connected to a host device and performing input / output processing; a plurality of storage devices; and a plurality of storage control nodes connected to the plurality of storage devices and performing input / output processing;
In any one of the nodes, there is provided means for managing which cache node has a control right with respect to a unit area uniquely determined from information for identifying predetermined data requested by the upper processing means. A storage system characterized by that.   The cache node receives a data request from the host device, searches the cache in the cache node, and responds to the data request from the host device using a cache area of the cache node in the case of a cache hit 20. The storage system according to claim 19, wherein the data access is performed. In the first cache node that has received the data request from the host device, the storage control node specified from the unit area uniquely determined from the data request is requested to control the unit area, and the control right If there is a second cache node having the above, the second cache node is prohibited from accessing other than the first cache node, and the corresponding cache area of the second cache node having the control right is set. And processing the data request of the host device, and registering and notifying that the control right is granted to the first cache node when there is no second cache node having the control right. ,
21. The storage according to claim 19 or 20, wherein the first cache node to which the control right is given performs input / output processing of the cache area using a cache of the first cache node. system. The control permission includes a control right that is a permission for one cache node to control the unit area,
The control right is assigned to a cache node by associating the unit area with a cache page unit,
The storage system according to any one of claims 19 to 21, which manages to which cache node a certain control right is assigned in one or a plurality of the storage control nodes. The cache node having the control right has permission to control the cache,
The cache node not having the control right reads or writes the corresponding cache page of the cache node having the control right in response to a data request when the cache node having the control right exists. The storage system according to claim 22, At the time of a cache hit, in the case of a data read request, the cache node transfers data from the corresponding cache page to the host device,
20. In the case of a data write request, when data is written to a corresponding cache page, processing completion is returned to the higher-level device, and the data is written to the storage device. Storage system. In the case of a cache miss, notify the cache node that manages the control right,
If there is a cache node that holds the control right of the corresponding cache page, if the cache node is a data read request, the mutual communication means is started from the corresponding cache page of the cache node that holds the control right. 23. The storage system according to claim 22, wherein the data is transferred via the network. In response to a data write request from the host device, the write data from the host device is written to the corresponding cache page of the cache node holding the control right via the mutual communication means,
23. The storage system according to claim 22, wherein completion of processing is returned to the host device, and write data from the host device is written to the storage device. The cache node is
A host device interface means connected to the host device, receiving a data read request or data write request from the host device, and processing data input / output between the host device and a cache node;
A data processing device;
With
The data processing device includes:
A command control means for receiving a data read request or data write request command received from the host apparatus received by the host apparatus interface means and controlling processing according to the command; and a data read request or data write request from the host apparatus A control right management node specifying means for specifying a node that manages a control right that is a permission for one cache node to control a unit area that is uniquely determined from:
Local memory,
Cache search processing, and cache control means for managing and controlling the cache stored in the local memory;
Storage space configuration information indicating to which storage control node a logical storage space is assigned, cache management information, a control memory unit for storing cache node control information,
A cache page unit that temporarily stores data input / output to / from the host device in units of pages;
With
A controller that controls data communication of the cache node and also handles communication with other cache nodes and storage control nodes via intercommunication means;
The storage system according to claim 22, comprising: The storage control node is
Storage device interface means connected to at least one storage device and performing data input / output between the storage device and the storage control node;
A data processing device;
With
The data processing device includes:
Storage device control means for controlling input / output command processing to the storage device;
A processing request for a control right from a plurality of cache nodes is executed with respect to a control right which is a permission for one cache node to control a unit area uniquely determined from a data read request or a data write request from the host device. Control right management means;
A control memory unit for storing storage control node control information and storage system device configuration information;
Local memory having control right control information indicating which node has control right for each cache page;
A controller connected to the mutual communication means and controlling communication with other cache nodes and storage control nodes;
The storage system according to claim 22, comprising: In the cache node,
The host device interface means receives a data read request or data write request command from the host device,
The command control means analyzes the command,
The cache control means receives the analysis result of the command control means, and determines whether or not the cache page corresponding to the requested data is already in the cache page part by searching the control memory part,
As a result of the determination, if the corresponding cache page exists on the cache page portion, after the cache page is exclusively processed, if it is a data read request, the corresponding data is read from the cache page of the cache page portion. Transfer to the host device,
28. The storage system according to claim 27, wherein if it is a data write request, the data sent from the host device is written to the corresponding cache page of the cache page portion. In the cache node,
If the corresponding cache page does not exist in the cache page part, the control right management node specifying means specifies the control right management node to be notified of the control right request for the corresponding page,
The control right management node specifying means refers to the storage space configuration information stored in the control memory unit, specifies a storage control node that is a control right management node to be notified of the control right request,
28. After specifying a corresponding control right management node, the controller is instructed to notify, and the control right request is notified to the specified storage control node via the mutual communication means. Storage system. In the storage control node that receives the request for the control right,
The controller receives the control request,
The control right management means determines a request for the control right and performs a control right determination process. At this time, the control right management means searches the control right management information to find the logical address of the corresponding page. Determine whether there is
If there is no control right holding node for the page corresponding to the control right request data, the requesting cache node is newly granted control right as the master of the page area and registered in the control right management information And
29. The storage system according to claim 28, wherein after registering the control right, the controller instructs the controller to notify, and notifies the requesting cache node that the control right has been registered via the mutual communication means. . The cache node that has received the control right secures the corresponding cache page in its own cache node and performs exclusive processing.
If the request from the higher-level device is a data read request, the storage control node is instructed to read the data corresponding to the storage control node, is stored in the corresponding cache page of the cache node, and is transferred to the higher-level device. The storage system according to claim 19. If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page, the processing completion is returned to the host device, and the data is written to the storage device. ,
28. The storage system according to claim 27, wherein after completion of the request processing of the host device, the cache control means of the cache node updates the cache management information of the control memory unit and releases the exclusion. The storage control node searches the control right management information to find the logical address of the corresponding page, and if it is found that the control right holding node exists, the storage control node requests the control right holding node Instruct the use request of the corresponding cache page of the cache node that is the node,
The control right management means of the storage control node instructs the controller to notify, via the mutual communication means, notifies the cache node of a request to use the corresponding cache page,
In the cache node forming the control right holding node,
In the controller, a request to use the corresponding cache page of the cache node is received from the storage control node,
The cache control means performs exclusive processing on the corresponding cache page, and notifies the address information for accessing the cache page from the controller to the cache node that is the control right request source node via the mutual communication means,
The cache node that has received the notification of the address information
If the request from the host device is a data read request, the data stored in the corresponding cache page of the cache node is transferred to the host device,
If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page of the cache node, the processing completion is returned to the host device, and the data is sent to the storage device. The storage system according to claim 28, wherein the storage system is written.   The storage system according to any one of claims 19 to 34, wherein the cache node and the storage control node are configured as an integrated node. A plurality of cache nodes having a cache connected to a host device and performing input / output processing;
Multiple storage devices,
A plurality of storage control nodes connected to a plurality of storage devices and performing input / output processing;
A storage system cache control method comprising:
In any one of the nodes, including a step of managing which cache node has permission for cache control for each unit area uniquely determined from information for identifying data requested by a host device. A storage system cache control method. The cache node receiving a data request from the host device and searching the cache with the cache node;
37. The storage system cache control method according to claim 36, wherein, in the case of a cache hit, the cache node performs a data access using a cache area. The cache node receiving a data request from the host device and searching the cache with the cache node;
In the case of a cache miss hit, the cache node requests a predetermined permission from the corresponding storage control node, and if there is a cache node having the permission, the cache node having the permission performs exclusive processing and has the permission. Processing the data request of the host device using the corresponding cache area of the cache node;
If there is no cache node having the permission, the cache node registers and notifies that the corresponding permission is granted to the requesting cache node; and
A cache node to which the corresponding permission is given, a step of performing cache control with the cache of the cache node;
The cache control method for a storage system according to claim 36, further comprising: It consists of a control right that is a permission for only one node to control a unit area uniquely determined from a data read request or data write request from the host device,
The method includes managing a control right assigned to a predetermined cache node for each cache page, to which cache node a certain control right is assigned in the plurality of storage control nodes. Item 37. The cache control method for a storage system according to Item 36. A cache node with control rights can control the cache without communicating with other cache nodes.
The cache node having no control right includes a step of reading and writing the corresponding cache page of the node having the control right when a cache node having the control right exists. Item 37. The cache control method for a storage system according to Item 36.   When a cache hit occurs, the cache node having the control right for the corresponding cache page transfers the data from the corresponding cache page to the host device if it is a data read request, and applies if it is a data write request. 40. The storage system cache according to claim 39, further comprising a step of returning processing completion to the host device when data is written to a cache page and writing the data to the storage device. Control method.   In the case of a cache miss, the node that manages the control right is notified, and if there is a node that holds the control right of the corresponding cache page, the cache node that has accepted the request determines that the request is a data read request. 40. The storage system cache control method according to claim 39, further comprising a step of transferring data from the corresponding cache page of the node holding the control right via the mutual communication means.   In the case of a data write request, the write data from the higher-level device is written into the corresponding cache page of the control right holding node via the mutual communication means, the processing completion is returned to the higher-level device, and the data 40. The storage system cache control method according to claim 39, further comprising a step of writing data into the storage device. In the cache node, receiving a data read request or data write request command from the host device, and analyzing the request in command control means;
Receiving the analysis result and determining whether the cache page corresponding to the requested data is already in the cache page part by searching the control memory part; and
If the corresponding cache page exists on the cache page portion, after the cache page is exclusively processed, if it is a data read request, the corresponding data is read from the cache page in the cache page portion and transferred to the host device. Process,
If it is a data write request, writing the data sent from the host device to the corresponding cache page on the cache page section;
The cache control method for a storage system according to claim 36, further comprising: If the corresponding cache page does not exist on the cache page part, the cache node specifies a control right management node that should notify a request for control right for the corresponding page;
Referring to the storage space configuration information stored in the control memory unit, specify the storage control node that is the control right management node that should be notified of the control right request, specify the corresponding control right management node, and then specify the specified Notifying the storage control node of a control right request;
The storage control node that receives the notification of the control right request receives the control right request, determines the control right request, and performs a control right determination process;
Searching the control right management information to determine whether a logical address of the corresponding page exists;
If the control right holding node of the page corresponding to the control right request data does not exist, the requested cache node is newly assigned as the master of the page area, and registered in the control right management information, After registering the control right, notifying the requesting cache node that the control right has been registered;
The cache node that has received the control right for the corresponding page secures the corresponding cache page in its own cache node and performs an exclusive process;
If the request from the host device is a data read request, instructing the storage control node to read data corresponding to the storage control node, storing it in the corresponding cache page of the cache node, and transferring to the host device;
40. The storage system cache control method according to claim 39, further comprising: If the request from the host device is a data write request, the step of writing the data sent from the host device to the corresponding cache page;
Returning completion of processing to the host device and writing the data to a storage device;
37. The cache control method for a storage system according to claim 36, wherein, after completion of the request processing of the host device, the cache node updates the cache management information of the control memory unit and releases the exclusion. When the control right management information is retrieved and there is a logical address of the corresponding page, and there is a control right holding node, the storage control node, for the control right holding node, corresponds to the cache node that is the control right requesting node. A step of instructing a request to use a cache page;
The storage control node notifying the cache node of a request to use the corresponding cache page via the mutual communication means;
The cache node that is the control right holding node of the corresponding cache page receives the use request of the corresponding cache page of the cache node from the storage control node in the controller of the cache node, and the cache control unit of the cache node A process of excluding the cache page;
A step of instructing the cache node controller to notify the cache node that is the control right requesting source of the address information for accessing the cache page after exclusion of the cache page, and notifying it via the mutual communication means When,
The cache node that has received the notification of the address information for accessing the cache page transfers the data stored in the cache page of the cache node to the host device if the request from the host device is a data read request When,
If the request from the host device is a data write request, the data sent from the host device is written to the corresponding cache page of the cache node, the processing completion is returned to the host device, and the data is sent to the storage device. Writing process;
40. The storage system cache control method according to claim 39, further comprising: A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
At least one processing unit of the plurality of processing units includes means for issuing a request to the management processing unit when the processing unit does not have a control right related to a unit area to be accessed;
The management processing unit receives a request from the processing unit, searches which processing unit currently has the control right of the unit area, and issues the request to the processing unit having the control right of the unit area And a means for instructing the processing unit to give information for accessing the cache area of the cache memory corresponding to the data in the unit area. A cache control method for a system having at least one cache memory and a plurality of processing units,
A processing unit that manages at least one of the plurality of processing units with respect to a unit area that is uniquely determined from an address of predetermined data in an address space to be cached. `` Management processing department '')
At least one processing unit of the plurality of processing units issues a request to the management processing unit when the processing unit does not have a control right relating to a unit area to be accessed;
The management processing unit receives a request from the processing unit, searches which processing unit currently has the control right of the unit area, and issues the request to the processing unit having the control right of the unit area Instructing the processing unit to give information for accessing the cache area of the cache memory corresponding to the data in the unit area;
A cache control method comprising: A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
When the first processing unit does not have the control right for the corresponding unit area, the first processing unit identifies the corresponding unit area or predetermined data in the unit area to the management processing unit. Means for transmitting a first signal containing information,
The management processing unit
Receiving the first signal from the first processing unit and referring to a storage unit that stores and manages which processing unit currently has the control right of the unit area, searches for the processing unit having the control right Means to
As a result of the search, when there is a second processing unit having a control right for the corresponding unit area, the usage notification of the corresponding unit area or data in the unit area is sent to the second processing unit. Means for transmitting a second signal of
With
The second processing unit gives the data in the cache area of the cache memory corresponding to the data in the corresponding unit area to the first processing unit in response to the second signal from the management processing unit. A cache control system comprising: means. A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
When the first processing unit does not have the control right for the corresponding unit area, the first processing unit identifies the corresponding unit area or predetermined data in the unit area to the management processing unit. Means for transmitting a first signal containing information,
The management processing unit
Receiving the first signal from the first processing unit and referring to a storage unit that stores and manages which processing unit currently has the control right of the unit area, searches for the processing unit having the control right Means to
As a result of the search, if there is a second processing unit having a control right for the corresponding unit area, the second processing unit has a control right for the corresponding unit area in the first processing unit. Means for transmitting a second signal for notifying
With
The first processing unit receives the second signal from the management processing unit, and notifies the second processing unit of a use notification of a cache area of the cache memory corresponding to the data in the corresponding unit area. A cache control system further comprising means for transmitting.   The second processing unit having the control right receives a signal from the management processing unit, permits only the first processing unit to update the predetermined data in the unit area, and other processing units 52. The cache control system according to claim 50, further comprising means for controlling not to permit updating.   The management processing unit includes means for granting the control right to the first processing unit that has requested the control right when there is no processing unit having the control right regarding the unit area as a result of the search. 52. The cache control system according to claim 50 or 51, wherein: The plurality of processing units are provided in a plurality of nodes connected to each other via communication means,
52. The cache control system according to claim 50, wherein a cache memory for temporarily storing data in the unit area is provided in one or more nodes. The plurality of processing units are provided in a plurality of nodes connected to each other via communication means,
52. The cache control system according to claim 50 or 51, wherein the cache memory is stored in a shared memory shared by the plurality of nodes.   52. The first processing unit identifies the management processing unit with reference to configuration information that stores correspondence between the unit area and the processing unit of the unit area. The described cache control system.   52. The cache control system according to claim 50, wherein the first processing unit includes means for determining whether or not the first processing unit has the right to control the unit area. .   The management processing unit searches the control information storing the correspondence between the unit area and the processing unit having the control right of the unit area, and specifies the second processing unit having the control right of the unit area 52. The cache control system according to claim 50 or 51, wherein:   The first processing unit sets the unit area as a page unit of the cache, and performs a hit check of the cache from information for identifying data requested by the upper processing means, thereby giving the right to control the unit area. 52. The cache control system according to claim 50, further comprising means for determining whether or not the first processing unit has.   52. When the first processing unit receives the second signal from the management processing unit, the first processing unit returns a response to a higher-level processing unit that has made a request to the first processing unit. The described cache control system. A method of performing cache control of at least one cache memory by a plurality of processing units,
When the first processing unit does not have a control right for a unit area uniquely determined from an address of predetermined data in the address space to be cached, the first processing unit determines which of the plurality of processing units For a processing unit that manages whether the processing unit has control over the unit area (referred to as a “management processing unit”), information that identifies the corresponding unit area or predetermined data in the corresponding unit area Transmitting a single signal;
The management processing unit receives the first signal from the first processing unit, refers to a storage unit that stores and manages which processing unit currently has the control right for the unit area, and controls the control right. Searching for a processing unit having
When there is a second processing unit having a control right related to the corresponding unit area as a result of the search, the management processing unit applies the corresponding unit area or the unit area to the second processing unit. Sending a second signal of data usage notification in
The second processing unit provides the first processing unit with data in the cache area of the cache memory corresponding to the data in the corresponding unit area in response to the second signal from the management processing unit. When,
A cache control method comprising: A method of performing cache control of at least one cache memory by a plurality of processing units,
When the first processing unit does not have a control right for a unit area uniquely determined from an address of predetermined data in the address space to be cached, the first processing unit determines which of the plurality of processing units For a processing unit that manages whether the processing unit has control over the unit area (referred to as a “management processing unit”), information that identifies the corresponding unit area or predetermined data in the corresponding unit area Transmitting a single signal;
The management processing unit receives the first signal from the first processing unit, refers to a storage unit that stores and manages which processing unit currently has the control right for the unit area, and controls the control right. Searching for a processing unit having
When the second processing unit having the control right for the corresponding unit region exists as a result of the search, the management processing unit has the control right for the corresponding unit region. Means for transmitting a second signal for notification to the first processing unit;
The first processing unit receives the second signal from the management processing unit, and notifies the second processing unit of a use notification of a cache area of the cache memory corresponding to the data in the corresponding unit area. Sending, and
A cache control method comprising:   The second processing unit having the control right receives the instruction from the management processing unit and permits the first processing unit to access the cache area corresponding to the predetermined data in the unit area. 63. The cache control method according to claim 61 or 62, comprising:   If there is no second processing unit having the right to control the unit area as a result of the search, the management processing unit controls the unit area to the first processing unit that has requested the control right. 64. The cache control method according to claim 61 or 62, further comprising a step of granting a right.   The cache according to claim 61 or 62, wherein the first processing unit specifies the management processing unit with reference to configuration information storing correspondence between the unit area and the unit area. Control method.   The management processing unit searches the control information storing the correspondence between the unit area and the processing unit having the control right of the unit area, and specifies the second processing unit having the control right of the unit area 63. The cache control method according to claim 61 or 62, wherein:   63. The request processing first processing unit notifies completion of use of the cache area after the access of the cache area corresponding to predetermined data in the unit area is completed. Cache control method.   The second processing unit having the control right receives a notification of completion of use of the cache area from the first processing unit, and cancels the permission of the cache area access of the first processing unit. 63. The cache control method according to claim 61 or 62, wherein:   64. The cache control method according to claim 61, wherein the first processing unit includes a step of determining whether or not the first processing unit has the right to control the unit area.   The first processing unit sets a unit area as a page unit of the cache, and performs a cache hit check from information for identifying data requested by the upper processing means, thereby giving the control right of the unit area the first area. 64. The cache control method according to claim 61 or 62, further comprising a step of determining whether or not the processing unit has one processing unit.   The first processing unit, when receiving the second signal from the management processing unit, returns a response to a higher-level processing unit that has made a request to the first processing unit. The described cache control method. A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
At least one processing unit of the plurality of processing units searches the management processing unit for a processing unit having the right to control the unit area when the processing unit does not have the right to control the unit area to be accessed. With means to issue requests to
The management processing unit receives a request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, a processing unit having the control right of the unit area Means for notifying the processing unit having the right to control the unit area of the information of the processing unit that issued the request, if present;
The processing unit having the right to control the unit area receives notification information from the management processing unit, notifies the processing unit that issued the request of the address information of the data in the unit area,
The processing unit that has issued the request uses the address information notified from the processing unit having the right to control the unit area to access data in the unit area to be accessed. Control system. A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
When at least one processing unit of the plurality of processing units does not have the control right for the unit area to be accessed, the processing unit having the control right for the unit area is searched for the management processing unit. Means to issue a request to
The management processing unit receives the request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, the processing unit having the control right of the unit area If there is, a means for notifying the processing unit having the control right of the unit area of the information of the processing unit that issued the request,
The processing unit having the right to control the unit area receives the notification information from the management processing unit, and in the case of read access, the processing unit that has issued the request has issued a cache corresponding to the data in the unit area. A cache control system for supplying data of a memory.   In the case of write access, the processing unit that has issued the request notifies the processing unit having the control right of the unit area that has received the notification information from the management processing unit to start transfer, and transfers the write data. The cache control system according to claim 73, wherein A cache control system having at least one cache memory and a plurality of processing units,
With respect to a unit area that is uniquely determined from the address of predetermined data in the address space to be cached, a processing unit (referred to as a `` management processing unit '') that manages which processing unit has control right,
When at least one processing unit of the plurality of processing units does not have the control right for the unit area to be accessed, the processing unit having the control right for the unit area is searched for the management processing unit. Means to issue a request to
The management processing unit receives the request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, the processing unit having the control right of the unit area A cache control system, comprising: means for notifying a processing unit that has issued the request of information on a processing unit having a right to control the unit area. The processing unit that issued the request receives the notification information from the management processing unit, and in the case of read access, notifies the usage request to the processing unit having the right to control the unit area,
The cache control according to claim 75, wherein the processing unit having the right to control the unit area transfers the data in the cache memory corresponding to the data in the unit area to the processing unit that issued the request. system.   The processing unit that has issued the request receives notification information from the management processing unit, and in the case of write access, transfers the write data to the processing unit having the right to control the unit area. 76. The cache control system according to claim 75. The processing unit that issued the request receives notification information from the management processing unit, and notifies the usage request to the processing unit having the right to control the unit area,
The processing unit having the right to control the unit area receives the use request, notifies the processing unit that issued the request of the address information of the data of the unit area to be accessed,
The processing unit that has issued the request performs access to data of the unit area to be accessed using the address information notified from the processing unit having the control right of the unit area. 75. A cache control system according to 75.   The management processing unit searches which processing unit currently has the control right of the unit area, and if the processing unit having the control right of the unit area does not exist as a result of the search, the management processing unit issues the request. The cache control system according to any one of claims 72 to 78, wherein a control right for the unit area is given to a processing unit. A cache control method comprising at least one cache memory and a plurality of processing units,
A processing unit that manages at least one of the plurality of processing units with respect to a unit area that is uniquely determined from an address of predetermined data in an address space to be cached. Function as `` management processing unit '')
At least one processing unit of the plurality of processing units searches the management processing unit for a processing unit having the right to control the unit area when the processing unit does not have the right to control the unit area to be accessed. Issuing a request to:
The management processing unit receives a request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, a processing unit having the control right of the unit area If present, notifying the processing unit having the right to control the unit area of the information of the processing unit that issued the request;
A processing unit having a control right of the unit area, receiving the notification information from the management processing unit, and notifying the processing unit that issued the request of the address information of the data in the unit area;
The processing unit that has issued the request uses the address information notified from the processing unit having the right to control the unit region to access data in the unit region to be accessed;
A cache control method comprising: A cache control method comprising at least one cache memory and a plurality of processing units,
A processing unit that manages at least one of the plurality of processing units with respect to a unit area that is uniquely determined from an address of predetermined data in an address space to be cached. Function as `` management processing unit '')
When at least one processing unit of the plurality of processing units does not have the control right for the unit area to be accessed, the processing unit having the control right for the unit area is searched for the management processing unit. Issuing a request to perform
The management processing unit receives the request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, the processing unit having the control right of the unit area If there is, the step of notifying the processing unit having the right to control the unit area of the information of the processing unit that issued the request;
The processing unit having the right to control the unit area receives the notification information from the management processing unit, and in the case of read access, the processing unit that has issued the request has issued a cache corresponding to the data in the unit area. Supplying memory data;
A cache control method comprising:   In the case of write access, the processing unit that has issued the request notifies the processing unit having the control right of the unit area that has received the notification information from the management processing unit, and transfers the control right of the unit area. The cache control method according to claim 81, wherein write data is transferred to a processing unit having the cache. A cache control method comprising at least one cache memory and a plurality of processing units,
A processing unit that manages at least one of the plurality of processing units with respect to a unit area that is uniquely determined from an address of predetermined data in an address space to be cached. Function as `` management processing unit '')
When at least one processing unit of the plurality of processing units does not have the control right for the unit area to be accessed, the processing unit having the control right for the unit area is searched for the management processing unit. Issuing a request to perform
The management processing unit receives the request from the processing unit, searches for which processing unit currently has the control right of the unit area, and as a result of the search, the processing unit having the control right of the unit area If there is, the step of notifying the processing unit that issued the request of the information of the processing unit having the right to control the unit area,
A cache control method comprising: The processing unit that has issued the request receives notification information from the management processing unit, and in the case of read access, a process of notifying a usage request to a processing unit that has the right to control the unit area;
In response to the use request, a processing unit having the right to control the unit area transfers the cache memory data corresponding to the data in the unit area to the processing unit that issued the request;
84. The cache control method according to claim 83, further comprising:   The processing unit that issued the request includes a step of receiving notification information from the management processing unit, and in the case of write access, transferring write data to a processing unit having a control right for the unit area. 84. The cache control method according to claim 83, wherein: The processing unit that issued the request receives notification information from the management processing unit, and notifies the usage request to the processing unit having the right to control the unit area;
A processing unit having a control right for the unit area, receiving the use request, and notifying the address information of the data of the unit area to be accessed to the processing unit that issued the request;
The processing unit that issued the request includes a step of accessing data of the unit area to be accessed using the address information notified from the processing unit having the control right of the unit area. 84. The cache control method according to claim 83, wherein: The management processing unit searches which processing unit currently has the control right of the unit area, and if the processing unit having the control right of the unit area does not exist as a result of the search, the management processing unit issues the request. 87. The cache control method according to claim 80, wherein a control right for the unit area is given to a processing unit.

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