JPH0973411A - Decentralized control system for access load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make sufficiently good use of the processing performance of the whole system by decentralizing access loads on respective central processor mechanisms by distribution matching an operation state. SOLUTION: The file decentralized type database system which is equipped with plural central processor mechanisms, a high-speed coupling mechanism that connects the central processor mechanisms loosely to one another and repeats communications, and an external storage device which stores files accessed by the respective central processor mechanisms and allows exclusive access to the files by file controls CPN arranged by the files constituting the database is equipped with a control CPN changing means which changes the file control CPN arranged corresponding to a specific file to another specified central processor mechanism and a load information gathering and providing means which monitors and collects the state of loads of access to the respective files and provides the access load information on each file control CPN.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an access load distribution control system having a plurality of central processing units (CPN), and more particularly, to each CPN of each file so that the access load is always distributed with optimum distribution. The present invention relates to an access load distribution control system that dynamically changes the arrangement of a network according to changes in operating conditions.

[0002]

2. Description of the Related Art Conventionally, as a parallel database system that operates on a computer system in which a plurality of CPNs are loosely coupled, a file sharing type parallel database system that shares the same file among a plurality of CPNs, and each file There are two types of file-distributed parallel database systems in which the CPN that performs access processing is fixed.

A file sharing type parallel database system allows access to all files to any CP.
Since it can be performed on the N, the processing capacity of each CPN can be effectively utilized by appropriately distributing the access processing to the file among a plurality of CPN independently of the file to be accessed. However, on the other hand, when updating a file, it is necessary to perform exclusive control or transfer update information to each other in order to maintain consistency with other CPNs, and the overhead due to such control cannot be avoided. . On the other hand, in the file-distributed parallel database system, since the CPN that performs access processing for each file is fixed, there is no need to perform the exclusive control or transfer of update information as described above when updating a file, The processing performance is superior to the shared file type. However, since the CPN that performs the access process is fixed for each file, the allocation to each CPN is decided in advance based on the access frequency for each file so that the access load is properly distributed to each CPN. Must. The method of determining the placement of each file in each CPN according to the conventional technique is roughly classified into two types. There are a method of dynamically determining the file management CPN at the time of starting access to the file (the invention described in Japanese Patent Laid-Open No. 4-303253) and a method of determining the arrangement in advance by a utility.

The method of dynamically determining the file management CPN at the start of access to a file is as follows. Which CPN each file has at the start (initial state) of the system.
When the (first) business program makes a request for access to a file while the system is in operation and is in a neutral state, the CPN that is executing the business program (first) Management rights are given to the file. In such a state, when another second business program requests access to the same file, the second business program causes the second business program to access the first CPN.
If it is executed in step 2, the CPN is directly accessed. When the second business program is executed in the second CPN different from the first CPN, the first CPN having the right to manage the file through the inter-CPN communication from the second CPN. Is requested to the CPN.

This method is used in an environment in which access to a file is serialized by occupying (exclusive use) of a file, as in batch processing.
Since the CPN executing each job exclusively manages the file, the communication between CPNs, which causes an increase in overhead, is eliminated, and the operational efficiency of the system can be effectively improved. On the other hand, like transaction work, multiple processes for the same file occur in parallel,
In an environment in which access requests are continuously made to the file, the CPN in which the transaction that occurred first is given the management right of the file to be processed, and then occurs. All access processing requests (loads) to the file from another transaction concentrate on the CPN.

On the other hand, in the method of determining the arrangement of the file management CPN in advance by the utility, the management CPN is set in advance for each file according to the access frequency (load status) to the file. Appropriate load distribution can be realized by the transaction work described above. However, in order to eliminate the inter-CPN communication while executing the batch job in this state, the job must be run on the file management CPN, so the load status does not always match the online business environment, and the load It is possible that the distribution is not done properly.

As described above, each method has advantages and disadvantages. Therefore, the database systems to which the current methods are applied are commercialized separately.

[0008]

In a system mainly for online business, the CPN arrangement for each file is often defined in advance when the system is constructed by the above-mentioned method. Then, when it becomes necessary to add / extend a file, or when the load distribution to each CPN becomes improper due to a change in the access status to the file, the file placement ( This is dealt with by changing the processing CPN).
That is, the specific file layout setting / changing process is
This is realized by using the auxiliary utility function provided in the conventional file distributed parallel database system.

Therefore, in the case of a system in which the load distribution to each CPN does not change (changes little) for a certain period, only the adjustment by the above-mentioned conventional utility function can suffice, but it depends on the operating hours. System that changes the file access status of online business significantly, or when executing a heavy-load batch business, each CPN
In the system in which the load distribution to the system significantly changes, there is a problem in that the capacity of the entire system cannot be fully utilized only by the adjustment by the conventional utility function.

An object of the present invention is to solve the above-mentioned problems and to allocate each CP in an appropriate distribution according to the operating status of the system.
CP of the file so that the access load to N is distributed
An object of the present invention is to provide an access load distribution control system capable of dynamically changing the N allocation and making full use of the processing capacity of the entire system.

[0011]

In order to achieve the above object, the access load distribution control system of the present invention comprises a plurality of central processing unit mechanisms each provided with an instruction processor and a main memory unit, and a central processing unit mechanism. A high-speed coupling mechanism for loosely coupling the central processing unit mechanisms to each other to relay communication communication between the central processing unit mechanisms, and an external storage device for storing files accessed by each of the central processing unit mechanisms. In the file distribution type database system in which the file management CPN, which is provided fixedly corresponding to each file constituting the database, is exclusively accessed, the management CPN The configuration includes a changing unit and a load information collecting / providing unit.

The above functions and are as follows. [Management CPN changing means] File management CPN to be arranged corresponding to any designated file during system operation
To another designated central processor facility. [Load Information Collecting / Providing Means] The status of the access load to each file is monitored and collected, and the collected access load information in each file management central processing unit mechanism is provided.

[0013]

In the access load distribution control system of the present invention, with the above-mentioned configuration, the file load is distributed so that the access load to each central processing unit is distributed with appropriate distribution according to the operating status of the system. Since the CPN arrangement can be dynamically changed, the processing capacity of the system as a whole can be maximized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an access load distribution control system of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a file distribution type database system to which the access load distribution control system of the present invention is applied, which is made into a multi-system by loosely coupling a plurality of instruction processors. 1 shows a database system that operates in an online environment.
In the figure, 10a to 10c are central processing unit mechanisms (hereinafter,
(Abbreviated as "CPN"), 11a to 11n are online terminals, 12 and 12a to 12n are external storage devices, 13
Is an input / output dynamic switching device (hereinafter abbreviated as "ACOD"), 14 is a high speed coupling mechanism (hereinafter abbreviated as "HCF"), 15 is a console, and 16a to 16c are operating systems (hereinafter "OS"). 17) is an online management program, 18 is a business program, 1
9a to 19c are database management programs (hereinafter,
(Abbreviated as "DBMS").

In FIG. 1, the CPN 10a includes online terminals 11a to 11a used for online processing.
11n are connected. In addition, the external storage device 12 in which a dictionary / directory for managing the management CPN information for each record or file in the database is stored is stored in the COD via the ACOD 13.
Since it is connected to the PN, it is possible to perform input / output to / from the external storage devices 12 and 12a to 12n from any CPN by referring to the dictionary / directory. CPN10a, CPN10b, CPN
Since the 10c are mutually connected by the HCF 14, arbitrary CPNs can communicate with each other (data transfer) via this. Furthermore, since the console 15 for operating all the CPNs is connected to the HCF, it is possible to control and monitor the entire system by inputting a predetermined command from the console 15.

On the CPN 10a, transaction control is performed according to inputs from the OS 16 and online terminals 11a to 11n that provide various functions such as monitoring and control of running programs and communication with other CPNs via the HCF 14. The online management program 17 for executing the transaction, the business program 18 for performing concrete transaction processing, and the DBMSs 19a to 19c for receiving and storing the data from the external storage devices 12 and 12a to 12n in response to the DB access request from the business program 18. To be executed.

As described in the prior art, in the file distributed database system, the management CPN for input / output for each file is defined in advance. There is no simultaneous access.

FIG. 2 is a diagram for explaining a database access process in the system of FIG. In the figure, in response to a DB access request issued from the business program 18 operating in the CPN 10a, the C of the file registered in the directory of the external storage device 12 is received.
The management CPN of the file to be accessed can be obtained by referring to the PN placement information. And DB
If it is an access to 12a, CPN1 is used as it is.
0a access. When the access request to the DB 12b is accepted, the DBMS 19a makes an access processing request to the DBMS 19b on the CPN 10b via the HCF. In response to this, DBMS19
b accesses the DB 12b and sends the result back to the CPN 10a via the HCF. DB12
The access request for c is also executed by the DBM in the same procedure as above.
Perform on S19c.

Therefore, if access requests to the DB managed by a particular CPN are concentrated, the CPN
The limit of the capacity of the system becomes the limit of the entire system. Therefore, by arranging the DBs so that the access requests (loads) to the DBs managed by each CPN are as even as possible, the capacity of the entire system can be maximized.

FIGS. 3 and 4 are diagrams for explaining the processing of collecting and monitoring the access load information in the system of FIG. 1, and FIG. 3 (a) shows the exchange of data between the components of the system. 3B shows the configuration of the aggregation table for aggregating the collected access load information, FIG. 4A shows the flow of the access load information aggregation processing, and FIG. 4B shows the aggregated access. The flow of the monitoring processing based on the load information is shown respectively (corresponding to "load information collecting and providing means" in claims).

In FIG. 3A, a DB access request is transmitted from the DBMS 19a to the CPN 10b via the HCF 14 in response to a DB access command written in the business program 18 operating in the CPN 10a.
In response to this, the DBMS 1 operating in the CPN 10b
9b executes access to the DB 12b, inputs / outputs data in response to the DB access request, and then uses the access result and processing cost (time required for input / output of data, etc.) as access load information to the CPN 10 via the HCF 14.
Send to a. After the DBMS 19a receives the access load information, the CPN 10a totalizes the processing costs using the totalization table in FIG. 3B.

In FIG. 4A, when the DB access request is issued from the DBMS 19a to the CPN 10b, the execution time is set in the final request time column in the tabulation table of FIG. 3B (step 411). The number in the request count column is incremented by 1 (step 412). Then, when the DB access is completed and the access load information is transmitted from the CPN 10b, the CP required for the processing concerned.
U time is calculated, and the calculated value is added to the stored value in the CPU time column corresponding to CPN 10b (step 41).
3).

On the other hand, in FIG. 4 (b), in addition to the processing of totaling access load information, the totaling table is monitored at regular intervals. That is, it is determined whether the number of requests or the CPU time in a certain CPN exceeds a specified value, based on the aggregation table of FIG. 3B (step 42).
1) After performing the process of displaying the load state of the CPN exceeding the specified value on the console (step 422) for all CPNs (step 423 = YE)
S) If there is a CPN that exceeds the specified value (step 424 = YES), the information of the CPN having the lowest access load among all CPNs is set to the CPN.
A series of processing of displaying the information on the console 15 together with the name of the database managed by the PN (step 425) and clearing this information (step 426) after a certain period of time has passed since the monitoring of the aggregation table was started. Repeat.

FIG. 5 is a diagram (No. 1) for explaining the change processing of the file management CPN by the access load distribution control system of the present invention (1), and the database is constructed by the command input operation from the console. It is a figure when the arrangement | positioning of each file is changed (equivalent to the "management CPN change means" in a claim).
In addition, FIGS. 5A and 5B show the correspondence between each file and the file management CPN that manages the file before and after the layout change.

In the system shown in FIG. 5A, the file DB-a having a high access frequency is CPN # 1 and the files DB-b and DB-c having a low access frequency are CPN # 2.
File DB-n is managed by CPN # n. If the access frequency to the file DB-a becomes low and the access frequency to the file DB-c becomes high due to the change of the access status to each file, the access load to the CPN # 2 increases and the CPN # 1 increases. Access load to When the bias of the access load becomes large to some extent or more, CPN # 1 and CPN # 2 will be displayed on the console 15 by the above-described access load information totaling / monitoring process. Therefore, when the operator inputs a command to change the arrangement of the file DB-b whose access frequency is lower than that of the console 15 from CPN # 2 to CPN # 1, the file DB-b is changed in all CPNs accordingly.
Management node processing is performed. That is, the CPN # 1 performs the connection process of the file DB-b which is to be newly managed, while the CPN # 2 performs the disconnection process of releasing the connection of the file DB-b. At the same time, CPN # 1 and CPN #
CPN other than 2 sets the management node information of file DB-b to C
Change from PN # 2 to CPN # 1. With the above processing, the system enters the state of FIG. 5B, and the access request for the file DB-b is accepted by CPN # 1. This series of change processing is performed as an extension of one command input operation by the operator.

FIG. 6 is a diagram (part 2) for explaining the file management CPN change processing by the access load distribution control system of the present invention (corresponding to "management CPN change means" in the claims). . The modification process of FIG. 6 is functionally almost the same as that described with reference to FIG.
Instead of inputting the command for changing the file arrangement from the console 15, by issuing the command from the business program 18 operating in CPN, each CP
It is possible to change the management CPN automatically without operator intervention when the access load on N is biased.

In addition, if there is a new batch job to be executed, if the CPN with the lowest access load is selected based on the above-mentioned aggregation table and the batch job is executed, the management CPN is set. The load distribution can be optimized without changing.

[0029]

As described in detail above, according to the access load distribution control system of the present invention, the access load to each central processing unit can be distributed in an appropriate distribution according to the operating conditions of the system. In addition, since it is possible to dynamically change the CPN arrangement of files, it is possible to obtain the effect of maximizing the processing capacity of the entire system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a file distributed database system to which an access load distributed control system of the present invention is applied.

FIG. 2 is a diagram for explaining an access process to a database in the system of FIG.

FIG. 3 is a diagram (No. 1) for explaining a process of collecting and providing access load information in the system of FIG.

4 is a diagram (No. 2) for explaining a process of collecting and providing access load information in the system of FIG.

FIG. 5 is a diagram (No. 1) for explaining the file management CPN change processing by the access load distribution control system of the present invention.

FIG. 6 is a diagram (No. 2) for explaining the file management CPN change processing by the access load distribution control system of the present invention;

[Explanation of symbols]

10a, 10b, 10c Central Processing Unit Mechanism (CPN) 11a-11n Online Terminal 12, 12a-12n External Storage Device 13 Input / Output Dynamic Switching Device (ACOD) 14 High-speed Coupling Mechanism (HCF) 15 Console 16a, 16b, 16c Operating System (OS) 17 Online management program 18 Business program 19a, 19b, 19c Database management program (DBMS)

Claims (3)

[Claims] 1. A plurality of central processing unit mechanisms each provided with an instruction processor and a main storage device for holding a program and data relating to the operation of the instruction processor, and the central processing unit mechanisms are loosely coupled to each other. And a high-speed coupling mechanism for relaying communication communication between each of the central processing unit mechanisms, and an external storage device for storing one or more files accessed by each of the central processing unit mechanisms. However, in the file distributed database system where the files are exclusively accessed by the file management CPN that is fixedly arranged in advance corresponding to each file that constitutes the database, it is specified during system operation. File management CPN to be placed corresponding to any specified file Management CPN changing means for changing to a management device mechanism, and load information collecting and providing means for monitoring and collecting the access load status to each file and providing the collected access load information in each file management CPN. An access load distribution control system characterized by having a configuration. 2. Based on the current access load information provided by the load information providing means, the access frequency is the lowest among the files exclusively accessed by the file management CPN whose access load exceeds a predetermined standard. 2. A file according to claim 1, wherein the file management CPN arranged corresponding to the selected file is changed to another central processing unit mechanism having the lowest access load. Distributed access load control system. 3. The central processing unit mechanism having the lowest access load is selected based on the current access load information provided from the load information providing means, and the designated batch job is assigned to the central processing unit mechanism. The access load distribution control system according to claim 1 or 2, wherein the system is configured to execute the access load distribution control system.