CN113377714A

CN113377714A - Target renaming method and device based on distributed storage system

Info

Publication number: CN113377714A
Application number: CN202110661804.6A
Authority: CN
Inventors: 陈坚; 刘华兴; 文刘飞
Original assignee: Shenzhen Sandstone Data Technology Co ltd
Current assignee: Shenzhen Sandstone Data Technology Co ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-09-10

Abstract

The embodiment of the invention relates to a target renaming method and a device based on a distributed storage system.A logical name and a service name are used as an attribute record of a logical target in the logical target, and the logical name and the service name are stored in different mapping tables of the same object by increasing the mapping of the logical name and the service name in the logical target; and in the storage cluster, mapping relations with the client, the block storage client and the SCS I gateway are still established by the logical name of the logical target. When the logical object is renamed, the mapping relation between the logical name and the service name in the logical object is actually added and modified, only one write request needs to be issued to the bottom-layer database, namely, only the mapping between the logical name and the service name of one object needs to be subjected to database configuration operation, so that the consistency of data is guaranteed, and the renaming efficiency is effectively improved.

Description

Target renaming method and device based on distributed storage system

Technical Field

The embodiment of the invention relates to the technical field of distributed storage systems, in particular to a method and a device for renaming a target based on a distributed storage system.

Background

In a distributed storage system, taking a Ceph distributed file system as an example, Ceph is a unified distributed file system designed for excellent performance, reliability and scalability.

In conventional storage systems, command, status and block data are primarily transferred between a host and a storage device via the SCSI protocol. However, with the advent of distributed storage and the need for a SCSI interface using the SCSI protocol, the iSCSI architecture is widely used.

The architecture of iSCSI (Internet Small Computer System Interface) defines a provider and a user of storage service as iSCSI target for converting SCSI commands and data in TCP/IP packets, and the iSCSI target is a storage service end; and an iSCSI initiator, as a storage client, for generating SCSI requests and encapsulating SCSI commands and data into TCP/IP packets to be sent to the IP network. The storage server side and the storage client side communicate with each other by using TCP, and the storage server side maps the block storage device into a volume and provides the volume to the storage client side, so that remote block storage service is realized.

However, in the prior art, in a distributed storage system based on a logical target, the logical target establishes a relationship with an SCSI gateway node, a block storage device, and a storage client for a core providing a block storage service, and related metadata information is persistently stored in multiple mapping tables of multiple underlying objects, if a user wants to modify a name of the logical target, the mapping tables of the multiple objects need to be changed with an operation instruction, which is difficult to ensure consistency of the operation instruction, and if a failure (such as a sudden network disconnection or power down) occurs in the middle of execution, inconsistency of the metadata information is caused, which may cause a related disk to be unable to be deleted but unavailable in a serious situation, resulting in many unnecessary troubles.

Disclosure of Invention

The embodiment of the application aims to provide a target renaming method and a target renaming device based on a distributed storage system, which are used for increasing the mapping between a logic name and a service name in a logic target, and only one object needs to be subjected to database configuration operation when the logic target is renamed, so that the database configuration operation of multiple objects caused by directly modifying the name is avoided, and the consistency of data is ensured.

In a first aspect, an embodiment of the present application provides a method for renaming a target based on a distributed storage system, where the method includes:

when a renaming operation instruction aiming at a logic target device is received, acquiring an original logic name and a target service name of the logic target device to be renamed;

if the logic target is the created target according to the original logic name in a metadata mapping table of the distributed storage system, verifying the validity of the target service name;

when the validity of the target service name passes verification, if an original service name exists in the logic target device, deleting the mapping relation between the original service name and the original logic name in the logic target device, adding the mapping relation between the target service name and the target logic name, and persistently storing the mapping relation in a metadata mapping table of a storage cluster;

and after the storage is successful, notifying an SCSI gateway to reload the metadata mapping table based on a subscription notification mechanism, and updating the mapping relation between the target service name and the target logic name based on the latest metadata mapping table.

In a second aspect, an embodiment of the present application further provides an apparatus for renaming a target based on a distributed storage system, where the apparatus includes:

the renaming operation receiving module is used for acquiring an original logic name and a target service name of the logic target to be renamed when a renaming operation instruction aiming at the logic target is received;

the validity verification module is used for verifying the validity of the target service name if the logic target is a created target according to the original logic name in a metadata mapping table of the distributed storage system;

a renaming module, configured to delete a mapping relationship between an original service name and an original logical name in the logical target if the original service name exists in the logical target when validity of the target service name passes verification, add a new mapping relationship between the target service name and the target logical name, and persistently store the new mapping relationship in a metadata mapping table of a storage cluster;

and the notification module is used for notifying the SCSI gateway to reload the metadata mapping table based on a subscription notification mechanism after the storage is successful, and updating the mapping relation between the target service name and the target logic name based on the latest metadata mapping table.

In a third aspect, an embodiment of the present application further provides a server, where the server includes at least one processor, and a memory, where the memory is communicatively connected to the at least one processor, and the memory stores instructions executable by the at least one processor, where the instructions are executed by the at least one processor, so as to enable the at least one processor to perform the above-mentioned method.

In a fourth aspect, an embodiment of the present application further provides a distributed storage system, including a server, an SCSI gateway, and a storage cluster; the server is the server according to the third aspect;

the server side persistently stores the mapping relation between the service name and the logic name of the renamed logic target in a metadata mapping table of the storage cluster;

the server side informs the SCSI gateway to reload the metadata mapping table based on a subscription notification mechanism;

the SCSI gateway loads the metadata mapping table based on the subscription notification mechanism, and updates the mapping relation between the service name and the logic name based on the metadata mapping table;

the SCSI gateway provides an access interface for the client based on a mapping relation between a service name and a logic name, and when the SCSI gateway exposes the logic target, if the service name of the logic target is set, the service name of the logic target is exposed to the outside, otherwise, the logic name of the logic target is exposed;

the client initiates an access request to the SCSI gateway through the access interface;

if the service name of the logic target device corresponding to the access request is set, the SCSI gateway converts the service name of the access request into a corresponding first actual logic name based on the mapping relation between the service name of the logic target device and the logic name;

if the service name of the logic target device corresponding to the access request is not set, the SCSI gateway takes the logic name of the logic target device as a second actual logic name of the access request;

and the client accesses the volume associated with the logical target device according to the first actual logical name or the second actual logical name.

In a fifth aspect, embodiments of the present application further provide a non-transitory computer-readable storage medium storing computer-executable instructions that, when executed by a distributed storage system, cause the distributed storage system to perform the method described above.

In a sixth aspect, the present application further provides a computer program product, where the computer program product includes a computer program stored on a non-volatile computer-readable storage medium, and the computer program includes program instructions, and when the program instructions are executed by a server, the server executes the method described above.

Compared with the prior art, the application has the following beneficial effects at least: in the method and the device for renaming the target based on the distributed storage system, the logical name and the service name are used as an attribute record of the logical target in the logical target, and the logical name and the service name are stored in different mapping tables of the same object by increasing the mapping between the logical name and the service name in the logical target; and in the storage cluster, mapping relations are still established between the client, the block storage client and the SCSI gateway by using the logical name of the logical target. When the logical object is renamed, the mapping relation between the logical name and the service name in the logical object is actually added and modified, only one write request needs to be issued to the bottom-layer database, namely, only the mapping between the logical name and the service name of one object needs to be subjected to database configuration operation, so that the consistency of data is guaranteed, and the renaming efficiency is effectively improved.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a model diagram of one embodiment of a distributed storage system of the present application;

FIG. 2 is a model diagram of another embodiment of a distributed storage system of the present application

FIG. 3 is a schematic block diagram of one embodiment of a distributed storage system of the present application;

FIG. 4 is a flowchart illustrating an embodiment of a method for renaming a target based on a distributed storage system according to the present application;

FIG. 5 is a schematic flowchart diagram illustrating another embodiment of a target renaming method in a distributed storage system according to the present application;

FIG. 6 is a flowchart illustrating a further embodiment of a method for renaming a target based on a distributed storage system according to the present application;

FIG. 7 is a flowchart illustrating a further embodiment of a method for renaming a target based on a distributed storage system according to the present application;

FIG. 8 is a schematic structural diagram of an embodiment of a target renaming apparatus based on a distributed storage system according to the present application;

FIG. 9 is a schematic structural diagram of an embodiment of a target renaming apparatus based on a distributed storage system according to the present application.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It should be noted that, if not conflicted, the various features of the embodiments of the invention may be combined with each other within the scope of protection of the present application. Additionally, while functional block divisions are performed in apparatus schematics, with logical sequences shown in flowcharts, in some cases, steps shown or described may be performed in sequences other than block divisions in apparatus or flowcharts. Further, the terms "first," "second," "third," and the like, as used herein, do not limit the data and the execution order, but merely distinguish the same items or similar items having substantially the same functions and actions.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Distributed storage systems, such as Ceph, are a unified distributed storage system designed for excellent performance, reliability, and scalability. In a distributed storage system, a storage device and a storage cluster are usually included, the storage device includes a storage server and a storage client, commands, states and block data are mainly transmitted between the storage cluster and the storage device through a SCSI protocol, and when the SCSI protocol is used, a SCSI interface is required, so that an iSCSI architecture is widely applied.

The architecture of iSCSI (Internet Small Computer System Interface) defines a provider and a user of storage service as iSCSI target, i.e., a storage server, for converting SCSI commands and data in TCP/IP packets, respectively; and an iSCSI initiator, i.e., a storage client, for generating SCSI requests and encapsulating SCSI commands and data into TCP/IP packets to be sent to the IP network. The storage server side and the storage client side communicate with each other by using TCP, and the storage server side maps the block storage device into a volume and provides the volume to the storage client side, so that remote block storage service is realized.

In a distributed storage system, there is usually a target (Linux target frame, tgt), which is an architecture proposed for creating and maintaining a storage server driver, and is indirectly integrated into the SCSI middle layer. When the storage server side pulls up the service process of the target device, the logic target device is created, the mapping relation between the logic target device and the storage client side and the block storage device is established, and the storage client side can access the block storage device through the logic target device.

In order to solve the problem of communication among multiple nodes, the ceph provides a watch/notify mechanism.

The watch/notify mechanism is similar to the information publish-subscribe schema: subscribe to messages through watch, publish messages through notify. That is, the client registers the fetch object with the OSD and maintains a session connection with the main OSD. The client can send a notification message and message content to all clients that have registered watch objects (also called watchers) and receive the notification when the watcher receives the notification, which allows the client to use any object as a synchronous communication channel.

The message notification and data synchronization between the logical target and the storage cluster are completed through a watch/notify mechanism, so that when the process of the logical target service is pulled up, a watch object is registered with the OSD, and then the storage cluster can complete the message notification from the storage cluster to the logical target only by notifying the watch object with a message.

When the metadata information is modified, the storage cluster updates the modified content to the logical target device in a notification mode, the logical target device reloads the metadata mapping table after receiving the notification, and updates the corresponding volume mapping relation based on the latest metadata mapping table, wherein the metadata information comprises the information of the logical target device; the correlation information of the logic target and the SCSI gateway; association information of the logical target and the block storage device; association information of the logical target and the client.

The storage client, namely the client, is a user of storage, and completes interaction with the logical target through an iSCSI protocol, and during the interaction, the method specifically comprises the following steps: the method comprises the steps of obtaining a logic target device list maintained in a logic target device, adding access control authority to the logic target device to access the block storage device associated under the logic target device, enabling the same storage client to authorize to access a plurality of logic target devices, and not accessing the block storage device associated on the logic target device for the storage client without authorization, so that the control of the access authority of the block storage device is achieved through the logic target device, the effect of isolating the block storage device is achieved, and finally, the client accesses the block storage device lunmask associated under the logic target device through the logic target device. In particular, it should be noted that, in each logical target, when a service name is specified, a mapping relationship between the service name and the logical name is included, and when a service name is not specified, a mapping relationship exists between the logical name and the client and the volume lun separately, and a model diagram thereof is shown in fig. 1.

Specifically, in the embodiment of the present application, the distributed storage system includes a server, a SCSI gateway, and a storage cluster; the server side persistently stores the mapping relation between the service name and the logic name of the renamed logic target in a metadata mapping table of the storage cluster;

In summary, the following steps: when the service name of the logic target device is not set, the storage client scans and acquires the logic name, and accesses the block storage device by using the logic name; when the service name of the logical target is set, the storage client scans for the service name and accesses the block storage device using the service name. The storage cluster still uses the logical name to establish the mapping relationship with the block storage device and the SCSI gateway, so an interconversion interface of the service name and the logical name needs to be implemented in the SCSI gateway to ensure correct interaction between the storage cluster and the storage client, and after the simplification of fig. 1, the lunmask simplified model diagram shown in fig. 2 is obtained.

Fig. 3 schematically shows a hardware structure of the server, and as shown in fig. 3, the server includes a memory 11 and a processor 12, and the processor 12 is connected to the memory 11. Those skilled in the art will appreciate that the architecture shown in FIG. 1 does not constitute a limitation on the servers, and that a distributed storage system may include more or fewer components than shown, or combine certain components, or split certain components, or have a different arrangement of components.

The memory 11, which is a non-volatile computer-readable storage medium, may be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The memory 11 may include a storage program area and a storage data area, wherein the storage program area may store an operating instruction system, an application program required for at least one function; the storage data area may store data created according to the use of the distributed storage system, and the like. Further, the memory 11 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, memory 11 may optionally include memory located remotely from processor 12, which may be connected to a server over a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The processor 12 is a control center of the server, connects various parts of the whole server by using various interfaces and lines, and performs various functions and processes of the server by running or executing software programs and/or modules stored in the memory 11 and calling data stored in the memory 11, thereby performing overall monitoring on the server, for example, implementing the target renaming method based on the distributed storage system according to any embodiment of the present application.

The processor 12 may be one or more, and one processor 12 is illustrated in fig. 1. The processor 12 and the memory 11 may be connected by a bus or other means, such as the bus connection in fig. 1. The processor 12 may include a Central Processing Unit (CPU), Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), controller, Field Programmable Gate Array (FPGA) device, or the like. The processor 12 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The method and the device for renaming the target based on the distributed storage system, provided by the embodiment of the application, may be executed by a server, and in particular, in some embodiments, the method may be executed by the processor 12.

Fig. 4 is a schematic flowchart of a method for renaming a target based on a distributed storage system according to an embodiment of the present application, where as shown in fig. 4, the method includes:

401: when a renaming operation instruction aiming at a logic target device is received, the original logic name and the target service name of the logic target device to be renamed are obtained.

When a client wants to modify the name of a logical target without changing a service scene, the client performs renaming operation on the logical target which wants to be renamed at the client, and the client issues a logical target renaming operation instruction through a configuration tool, at this time, a distributed storage system receives the renaming operation instruction aiming at the logical target, and then obtains an original logical name and a target logical name of the logical target to be renamed.

In order to persistently store the information of the logical target, as shown in fig. 2, in the logical target, the logical name and the service name are recorded as attributes of one logical target, so that, at the time of renaming, the original logical name of the logical target to be renamed needs to be acquired, and the target service name that the user wants to rename needs to be acquired.

402: and if the logic target is the created target according to the query of the original logic name in a metadata mapping table of the distributed storage system, verifying the legality of the target service name.

After the original logical name of the logical target device to be renamed is obtained, whether the logical target device to be renamed is a created target device or not is inquired in a metadata mapping table of a distributed storage system according to the original logical name, and if yes, the validity of the target service name is verified.

It will be appreciated that since the renaming operation is primarily for logical targets that have been created successfully, the renaming operation is not possible for logical targets that have not been created successfully.

When the legality of the target service name is verified, the legality is verified through a configuration tool, and the legality mainly verifies whether the target service name follows the naming rule of the service name and whether conflicts with the service names of other logic targets.

403: when the validity of the target service name is verified, if an original service name exists in the logic target device, deleting the mapping relation between the original service name and the original logic name in the logic target device, and adding the mapping relation between the target service name and the target logic name.

Specifically, when the validity of the target service name passes verification, because a condition that the service name is not set when the logical target is created exists, it is determined whether an original service name exists in the logical target, that is, it is determined whether the service name is set in the logical target to be renamed, and if the original service name exists in the logical target, it indicates that a mapping relationship between the original service name and the original logical name exists in the logical target to be renamed, at this time, it is necessary to delete the mapping relationship between the original service name and the original logical name in the logical target, add the mapping relationship between the target service name and the target logical name, and persistently store the mapping relationship in the metadata mapping table of the storage cluster.

Correspondingly, when the validity of the target service name is verified, if the original service name does not exist in the logic target device, setting the attribute of the target service name, and adding the mapping relation between the target service name and the target logic name.

More specifically, the configuration tool rbdtool directly calls a logical target rename interface provided by the cluster to complete the setting of the service name of the logical target, and updates the metadata mapping table maintained in the cluster. When renaming, in a target, NODES, MAP, LIST object, with the logic name as key, inquiring the information of the logic target device to be renamed, updating the attribute of the service name field therein, with the logic name as key, with the updated information as value, and overwriting; and recording the mapping information of the service name and the logical name by taking the service name as key and the logical name as value, namely storing the mapping information in the target. If the service name is not null in the original logical target information, the mapping relationship between the original service name and the logical name is also deleted.

404: and after the storage is successful, notifying an SCSI gateway to reload the metadata mapping table based on a subscription notification mechanism, and updating the mapping relation between the target service name and the target logic name based on the latest metadata mapping table.

Specifically, after the metadata mapping table stored in the storage cluster is successfully stored, the configuration tool pushes information of the logical target through notify, based on a subscription notification mechanism, the server informs the SCSI gateway, and after the SCSI gateway receives the notify message, the metadata mapping table is reloaded, and the mapping relationship between the target service name and the target logical name is updated based on the latest metadata mapping table.

In the storage cluster, mapping relations with the storage client, the block storage device and the SCSI gateway are still established respectively by using the logical name of the logical target, and when the SCSI gateway exposes the logical target to the outside, if the service name of the logical target is set, the service name is exposed; otherwise, the logical name is exposed, as shown in fig. 2, fig. 2 is a simplified model diagram of lunmask, and in tgtnode2, there is a case where a service name is not specified, and at this time, logical name 3 is directly exposed. And after the SCSI gateway loads and exposes the updated logic target externally, the SCSI gateway is enabled to provide an access interface of the client.

And based on a subscription notification mechanism, enabling the SCSI gateway to subscribe a change notification of the logic target in the distributed storage system, namely, the SCSI gateway knows that the logic target to be renamed has completed the renaming operation and obtains a target logic name of the logic target after the renaming operation.

After the SCSI gateway provides an access interface for the client, the client initiates a scanning action to the SCSI gateway to attempt to acquire a logical target device list, after the client acquires the logical target device list, the client can initiate an access request, if the initiated access request is to access a renamed logical target device, if the renamed logical target device is designated with a service name, the service name of the access request is converted into a renamed logical target device actual logical name by the SCSI gateway due to the exposed service name; if the renamed logical target is not assigned with a service name, the SCSI gateway takes the logical name of the access request as the actual logical name of the renamed logical target without conversion because the exposed logical name is the logical name.

Therefore, it is not known to the client whether the name of the logical target in the scan result is a service name or a logical name. When the client logs in, the obtained logical target device name is used for completing the login.

After the client obtains the target device list, the client can access the volume associated with the logical target device according to the logical target device.

In the embodiment of the application, a logic name and a service name are taken as an attribute record of a logic target in a logic target device, and the logic name and the service name are stored in different mapping tables of the same object by increasing the mapping of the logic name and the service name in the logic target device; and in the storage cluster, mapping relations are still established between the client, the block storage client and the SCSI gateway by using the logical name of the logical target. When the logical object is renamed, the mapping relation between the logical name and the service name in the logical object is actually added and modified, only one write request needs to be issued to the bottom-layer database, namely, only the mapping between the logical name and the service name of one object needs to be subjected to database configuration operation, so that the consistency of data is guaranteed, and the renaming efficiency is effectively improved.

In some embodiments, a logical target may also be created, and thus, as shown in fig. 5, the method may further include:

501: when a creation operation instruction of a logic target is received, determining a logic name of the logic target to be created and an SCSI gateway associated with the logic target to be created, and determining whether the logic target to be created is created;

502: if the logical target device to be created is not created, verifying whether a service name to be created is specified in the logical target device to be created;

503: if the service name to be created is specified in the logical target device to be created, verifying whether the service name to be created conflicts with the logical name and the service name of the created logical target device;

504: when the service name to be created is not in conflict with the service name and the logic name of the created logic target, judging that the service name to be created is legal, and creating a first logic target based on the service name to be created and the logic name to be created, wherein the first logic target records the mapping relation between the service name to be created and the logic name to be created and records the mapping relation between the service name to be created and the SCSI gateway related to the logic target to be created;

505: based on the subscription notification mechanism, notifying the service name of the first logical target of the SCSI gateway associated with the logical target to be created, so that the service name of the first logical target is exposed when the SCSI gateway exposes the first logical target.

Specifically, during creation, whether the service name to be created conflicts with the created logic name and service name of the logic target is verified, and if the service name to be created does not conflict with the created logic name and service name of the logic target, the service name to be created is judged to be legal; if so, modification of the service name to be created may be prompted. And when the service name to be created is legal, directly creating a first logic target based on the service name to be created and the logic name to be created. Meanwhile, the first logic target records the mapping relation between the service name to be created and the logic name to be created, and records the mapping relation between the service name to be created and the SCSI gateway related to the logic target to be created.

In some of these embodiments, after step 502, the method may further comprise:

if the service name to be created is not specified in the logical target to be created, verifying whether the logical name of the logical target to be created conflicts with the logical name and the service name of the created logical target;

when the logic name of the logic target to be created is not in conflict with the logic name and the service name of the created logic target, creating a second logic target based on the logic name of the logic target to be created;

notifying a SCSI gateway associated with the to-be-created logical target of the logical name of the second logical target based on the subscription notification mechanism, so that the SCSI gateway exposes the logical name of the second logical target when exposing the second logical target.

Correspondingly, when the service name to be created is not specified in the logic target to be created, the second logic target is directly created, and the mapping relation between the service name and the logic name does not exist in the second logic target. Then, when notifying the SCSI gateway associated with the logical target to be created, a message notification is sent, that is: when the service name is not specified, the service name acquired by the SCSI gateway associated with the logic target to be created is an empty character string; correspondingly, if the service name is specified, the service name acquired by the SCSI gateway is the actual service name, when the SCSI gateway associated with the logical target to be created exposes the target, the logical name is exposed if the service name is a null character string, and the actual service name is exposed if the service name is the actual service name.

Furthermore, the client sends a creation operation instruction of the logical target through the configuration tool, and in the creation operation instruction, a logical name to be created of the logical target to be created, at least one piece of accessed gateway information and a service name of an optional specified logical target must be specified.

In the process of creating a logic target, a configuration tool directly calls a logic target creation interface provided outside a storage cluster, creation of the logic target is completed, and logic target information (key is a logic target logic name, value is a logic target logic name, a logic target service name (if the field value is null if not specified), read-write attributes, types, creation time and access nodes) is written into a target. Assigning an id to the logical target, and writing logical target information (key is logical name of logical target, value is id, read-write attribute, type) into node. After the metadata is updated, the configuration tool pushes the information of the created logical target to inform the SCSI gateway associated with the logical target to be created through a subscription notification mechanism, and the SCSI gateway reloads the metadata mapping table after receiving the notiyf message and updates the corresponding volume mapping relation based on the latest metadata mapping table.

The user may also perform a query operation on the logical target, and in some embodiments, as shown in fig. 6, the method may further include:

601: when receiving an inquiry operation instruction of a logic target, acquiring a created logic target list;

602: returning each queryable target device in the logic target device list and the attribute of the queryable target device, if the service name is appointed in the queryable target device, displaying the service name attribute of the queryable target device as the service name; and if the service name is not specified in the inquired target device, displaying that the service name attribute of the inquired target device is null.

During query, when a user queries the logical target, the server returns all the created logical targets to obtain a logical target list. The user may click on each logical target in the list and the server returns the logical target and its respective attributes, as shown in table one below,

watch 1

Obviously, since the service name attribute is added to the logical target, the service name attribute is also returned during query, and other attributes including a creation timestamp attribute, a read-write attribute, and a type attribute are also returned, where ISCSI/FC is two protocol attributes. And, in the logical target, if the service name is specified in the logical target to be queried, returning the service name, for example, the name corresponding to the service name attribute in the logical target 1 is B.

Correspondingly, when the service name in the logical target device to be queried is not set, the query result with the service name to be queried being null is returned, that is, the value of the field of the relevant service name in the echoing is null, such as the service name in the logical target device 4 echoing < null line >.

The user may also perform a delete operation on the created logical target, and in some embodiments, as shown in fig. 7, the method may further include:

701: when a deleting operation instruction for deleting a logic target is received, acquiring a logic name to be deleted of the logic target to be deleted corresponding to the deleting operation instruction;

702: according to the logic name to be deleted, inquiring whether the logic target to be deleted is a created target or not in the metadata mapping table, and inquiring whether the logic target to be deleted has a mapping relation with a volume and whether the logic target to be deleted has a mapping relation with a client or not;

703: if the logical target to be deleted is the created target, and a mapping relation exists between the logical target to be deleted and the volume and/or between the logical target to be deleted and the client, failure deletion is prompted;

704: if the logical target to be deleted is a created target, the logical target to be deleted does not have a mapping relation with the volume, and the logical target to be deleted does not have a mapping relation with the client, judging whether a service name to be deleted exists in the logical target to be deleted;

705: if the service name to be deleted exists, deleting the logic name to be deleted, the service name to be deleted, the mapping relation between the logic name to be deleted and the service name to be deleted and the target device information of the logic target device to be deleted in the metadata mapping table;

706: if the service name to be deleted does not exist, deleting the logic name to be deleted of the logic target device to be deleted and the target device information of the logic target device to be deleted in the metadata mapping table;

and 707, notifying a SCSI gateway associated with the logical target to be deleted to reload the metadata mapping table based on the subscription notification mechanism.

Specifically, since the logical target adds the service name attribute and adds the mapping between the service name and the logical name to the target. Therefore, when a deletion operation instruction for deleting a logical target is received, if the logical target to be deleted is a created target, a mapping relation does not exist between the logical target to be deleted and a volume, and a mapping relation does not exist between the logical target to be deleted and a client, whether a service name to be deleted exists in the logical target to be deleted is judged, if yes, a query is initiated and a service name to be deleted is obtained in the metadata mapping table target. And will also delete information about the logical target in the node targets list object.

And if the service name to be deleted does not exist, deleting the logical name to be deleted of the logical target device to be deleted and the target device information of the logical target device to be deleted in the metadata mapping table. Namely, when the service name in the logical target device to be deleted is empty, the mapping relation between the logical name to be deleted and the service name to be deleted does not need to be deleted, and the logical name to be deleted of the logical target device to be deleted and the target device information of the logical target device to be deleted can be deleted directly.

Correspondingly, if the mapping relationship exists between the logical target device to be deleted and the volume and/or between the logical target device to be deleted and the client, failure of deletion is prompted.

And after the deletion operation is finished, notifying a SCSI gateway associated with the logic target to be deleted to reload the metadata mapping table based on the subscription notification mechanism.

After the metadata is updated, the configuration tool rbdtool informs an SCSI gateway (i.e. tgt) through notify pushing of logical target information, tgt reloads the metadata mapping table after receiving notify information, and updates the corresponding volume mapping relation based on the latest metadata mapping table.

Correspondingly, as shown in fig. 8, an embodiment of the present application further provides a target renaming apparatus based on a distributed storage system, which may be applied to the distributed storage system, for example, the distributed storage system shown in fig. 1, where the target renaming apparatus 800 based on the distributed storage system includes:

a renaming operation receiving module 801, configured to, when a renaming operation instruction for a logical target is received, obtain an original logical name and a target service name of the logical target to be renamed;

a validity verifying module 802, configured to verify validity of the target service name if the logical target is a created target according to the original logical name, which is queried in a metadata mapping table of the distributed storage system;

a renaming module 803, configured to delete the mapping relationship between the original service name and the original logical name in the logical target device, add a new mapping relationship between the target service name and the target logical name, and persistently store the new mapping relationship in the metadata mapping table of the storage cluster, if the original service name exists in the logical target device when the validity of the target service name is verified;

a notifying module 804, configured to notify the SCSI gateway to reload the metadata mapping table based on a subscription notification mechanism after the storage is successful, and update the mapping relationship between the target service name and the target logical name based on the latest metadata mapping table.

In some embodiments, renaming module 803 is further configured to:

and when the validity of the target service name passes the verification, if the original service name does not exist in the logic target device, setting the attribute of the target service name, and adding the mapping relation between the target service name and the target logic name.

In some embodiments, as shown in FIG. 9, the distributed storage system based target renaming apparatus 800 further comprises an access module 805 for:

providing an access interface for a client through the SCSI gateway based on the mapping relation between the target service name and the target logic name, wherein the access interface is used for receiving an access request of the client, and if the renamed logic target exposes the service name, converting the service name of the access request into the actual logic name of the renamed logic target; and if the renamed logical target device exposes the logical name, converting the logical name of the access request into the actual logical name of the renamed logical target device, and accessing the volume associated with the renamed logical target device according to the actual logical name.

In some embodiments, distributed storage system based target renaming apparatus 800 further comprises a creation module 806 for:

when a creation operation instruction of a logic target is received, determining a logic name of the logic target to be created and an SCSI gateway associated with the logic target to be created, and determining whether the logic target to be created is created;

if the logical target device to be created is not created, verifying whether a service name to be created is specified in the logical target device to be created;

if the service name to be created is specified in the logical target device to be created, verifying whether the service name to be created conflicts with the logical name and the service name of the created logical target device;

when the service name to be created is not in conflict with the service name and the logic name of the created logic target, judging that the service name to be created is legal, and creating a first logic target based on the service name to be created and the logic name to be created, wherein the first logic target records the mapping relation between the service name to be created and the logic name to be created and records the mapping relation between the service name to be created and the SCSI gateway related to the logic target to be created;

based on the subscription notification mechanism, notifying the service name of the first logical target of the SCSI gateway associated with the logical target to be created, so that the service name of the first logical target is exposed when the SCSI gateway exposes the first logical target.

In some embodiments, the creating module 806 is further configured to:

In some embodiments, the apparatus 800 further comprises a query module 807 further configured to:

when receiving an inquiry operation instruction of a logic target, acquiring a created logic target list;

returning each queryable target device in the logic target device list and the attribute of the queryable target device, if the service name is appointed in the queryable target device, displaying the service name attribute of the queryable target device as the service name; and if the service name is not specified in the inquired target device, displaying that the service name attribute of the inquired target device is null.

In some embodiments, the apparatus 800 further comprises a deletion module 808 to:

when a deletion operation instruction of a logic target device is received, acquiring a logic name of the logic target device to be deleted;

inquiring whether the logical target to be deleted is a created target or not in the metadata mapping table according to the logical name of the logical target to be deleted, and inquiring whether the logical target to be deleted has a mapping relation with a volume and whether the logical target to be deleted has a mapping relation with a client or not;

if the logical target to be deleted is the created target, and a mapping relation exists between the logical target to be deleted and the volume and/or between the logical target to be deleted and the client, failure deletion is prompted;

if the logical target to be deleted is a created target, the logical target to be deleted has no mapping relation with the volume, and the logical target to be deleted has no mapping relation with the client, judging whether a service name to be deleted exists in the logical target to be deleted;

if the service name to be deleted exists, deleting the logic name to be deleted, the service name to be deleted, the mapping relation between the logic name to be deleted and the service name to be deleted and the target device information of the logic target device to be deleted in the metadata mapping table;

if the service name to be deleted does not exist, deleting the logic name to be deleted of the logic target device to be deleted and the target device information of the logic target device to be deleted in the metadata mapping table;

and notifying a SCSI gateway associated with the logic target to be deleted to reload the metadata mapping table based on the subscription notification mechanism.

It should be noted that the device has the corresponding functional modules and beneficial effects of the method. For technical details which are not described in detail in the device embodiments, reference is made to the methods provided in the embodiments of the present application.

Embodiments of the present application also provide a non-transitory computer-readable storage medium storing computer-executable instructions, which are executed by one or more processors, such as one processor 12 in fig. 1, and enable the one or more processors to perform the method for renaming a target based on a distributed storage system in any of the method embodiments, for example, to perform the method steps 401 to 404 in fig. 4, the method steps 501 to 505 in fig. 5, the method steps 601 to 602 in fig. 6, and the method steps 701 to 707 in fig. 7; the functions of the modules 801 and 804 in fig. 8 and the modules 801 and 808 in fig. 9 are realized.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Through the above description of the embodiments, those skilled in the art will clearly understand that the embodiments may be implemented by software plus a general hardware platform, and may also be implemented by hardware. It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware related to instructions of a computer program, which can be stored in a computer readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for renaming a target based on a distributed storage system, the method comprising:

2. The distributed storage system based target renaming method of claim 1, wherein the method further comprises:

3. The distributed storage system based target renaming method according to any one of claims 1 to 2, wherein the method further comprises:

4. The distributed storage system based target renaming method according to claim 3, wherein after the verifying whether the service name to be created is specified in the logical target to be created, the method further comprises:

5. The distributed storage system based target renaming method according to any one of claims 1 to 2, wherein the method further comprises:

6. The distributed storage system based target renaming method according to any one of claims 1 to 2, wherein the method further comprises:

7. An apparatus for renaming a target based on a distributed storage system, the apparatus comprising:

8. A server, comprising at least one processor, and a memory communicatively coupled to the at least one processor, the memory storing instructions executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-6.

9. A distributed storage system is characterized in that the distributed storage system comprises a server, an SCSI gateway and a storage cluster; the server is the server according to claim 8;

10. A non-transitory computer-readable storage medium having stored thereon computer-executable instructions that, when executed by a server, cause the server to perform the method of any one of claims 1-6.