JPH09292999A - Transaction exclusive system in cluster system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate exclusive control at the tine of accessing a common data base in a user program and to improve the reliability by executing transaction only by one task in a host computer having execution right. SOLUTION: When a transaction is outputted from a transaction input means C1 the transaction identification processing means of the host computer A checks whether the transaction can be executed or not. The transaction identification processing means 3 judges whether it is transaction (signal host transaction) requiring an exclusive processing or not. When it is the single host transaction, an execution right check means 4 is started and whether execution right exists in the self host computer or not. When the self hod computer has execution right in the judgment, a transaction execution means 5 executes transaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cluster system, and more particularly to an information processing system for performing transaction processing in the cluster system, and more particularly to a transaction exclusive control system.

[0002]

2. Description of the Related Art As an example of a task scheduling method in a conventional multiprocessor system, for example, Japanese Patent Laid-Open No. 6-119300 discloses a task scheduling method for efficiently using resources without causing extra processing overhead. The task scheduling method is described in which each task informs the scheduler of its own processing characteristics, and the resources to be used are selected by the scheduler program according to the available resources. ing.

Further, in Japanese Patent Laid-Open No. 1-205369, in a means for determining a computer to execute a job among a plurality of computers, a computer to execute the job is automatically designated based on the information included in the job control limit. As a system having means, the system can be effectively used without being aware of the system configuration, and the computer that automatically executes the job is determined from the information of the execution class of the submitted job. Such a multi-computer type configuration has been proposed.

Further, for example, Japanese Patent Laid-Open No. 63-271538.
Japanese Patent Publication proposes a method of automatically operating a job according to the job schedule definition information corresponding to a logical host system by storing the job schedule definition information in a shared storage device as a job automatic operation control method in a loosely coupled multiple system. ing.

As described above, when there are a plurality of computers (or processing subjects such as processors), various types of conventional methods have been used as methods for determining which computer performs the processing.

[0006]

However, the above-described execution computer determination method for a plurality of computers has a problem that exclusive control must be performed on the user program side. The reason for this is that none of the methods described in the above publications has a mechanism for sequentially processing a series of transactions requiring exclusive processing.

In the case of executing transactions in a computer system, it is necessary to perform exclusive processing of the database if the database inconsistency occurs when the transactions are executed simultaneously.

At this time, in order to simplify the program, the exclusive control process is not performed by the program, and the task that executes the transaction is limited to one.
There is a method of performing exclusive control with one transaction operating at the same time. This is called a "single task transaction".

[0009] By the way, in a cluster system in which a plurality of host computers are shared and a database is shared by the plurality of host computers, transactions are executed in each of the host computers that compose the cluster. Transactions may be executed simultaneously depending on the number of host computers to be configured.

Therefore, the function of the single task transaction described above cannot be used, and as a result, it is necessary to incorporate exclusive processing into the program, and in addition to modification and modification of the user program, control for exclusive processing is complicated. Had changed.

The present invention has been made in view of the above circumstances, and an object thereof is to execute a transaction by only one task of a host computer having an execution right to access a shared database in a user program. To provide a cluster system that does not require exclusive control at the time, does not need to change user programs when moving from a single system to a cluster system, and can significantly improve maintainability and reliability. It is in.

Further, according to the present invention, by executing in a cluster system, even if a host computer executing a transaction goes down, recovery processing works on another host computer, so that the reliability is improved. The purpose is to provide.

[0013]

In order to achieve the above object, the present invention provides a cluster system comprising a plurality of host computers, the plurality of host computers sharing a database and performing online transaction processing. Execution right storing means for storing whether the host computer has the execution right, execution right changing means for changing the information of the host computer having the execution right stored in the execution right storing means, and input from the transaction input means The transaction identification processing means for identifying the generated transaction and whether the corresponding host computer has the execution right for the transaction identified by the transaction identification processing means as a transaction to be processed by a single host computer. The fruit Execution right checking means for referring to the right storing means, transaction executing means for executing a transaction when the host computer has the execution right by the execution right checking means, and execution at the time of checking the execution right checking means Execution right acquisition means for acquiring the execution right when there is no host computer that has acquired the right, and execution right release means for releasing the execution right when the transaction identification processing means determines that the transaction cannot be executed. And a monitoring means for another host that monitors whether or not another host computer is operating, an inter-host communication means for transferring data between the host computers, and a shared storage means for storing transaction information and the like. Provides an exclusive control method.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of an embodiment of the present invention. In FIG. 1,
As a plurality of computers, two computers are shown for ease of explanation, and for the convenience of drawing, the internal configuration of one host computer A is shown.
The configuration of the other host computer B is assumed to be the same as the internal configuration of the host computer A.

Referring to FIG. 1, in the embodiment of the present invention, a host computer A has an execution right storing means 1 for storing which host computer has an execution right, and an execution right for the execution right storing means 1. A transaction processed by a single host computer by the transaction identification processing unit 3 and the transaction identification processing unit 3 for identifying the transaction input from the transaction input unit C and the execution right changing unit 2 for changing the information of the owned host computer. For the transaction identified as existing, whether or not the host computer has the execution right is checked by referring to the execution right storage means 1.
The execution right check means 4 is provided.

Further, in the embodiment of the present invention, the execution right checking means 4 executes the transaction when the host computer has the execution right, and the execution right checking means 4 executes the execution right at the time of checking. Execution right acquisition means 6 that acquires the execution right when there is no host computer that has acquired the execution right, and execution right release means 7 that releases the execution right when the transaction identification processing means 3 determines that the transaction cannot be executed. And another host monitoring means 8 for monitoring whether or not another host computer is operating, an inter-host communication means 9 for performing data transfer between host computers, and a shared storage means 10 for storing transaction information and the like. I have it.

Here, the execution right storage means 1 may be shared by all the host computers or may be owned by each host computer. Further, the execution right may be unique to the cluster system, or may be present for each concept of classes divided into certain categories.

FIG. 2 is a flowchart for explaining the operation of the embodiment of the present invention. The processing flow of the embodiment of the present invention will be described below with reference to the configuration block diagram of FIG. 1 and the flowchart of FIG.

For example, when a transaction is input from the transaction input means C, the host computer A
The transaction identification processing means 3 checks whether or not this transaction can be executed (step 21).

If the input transaction cannot be executed, the execution right releasing means 7 is activated (step 22), and necessary information is shared by the shared storage means 10 so that the transaction can be executed by another host computer. (Step 23).

The execution right releasing means 7 activates the execution right changing means 2 and requests to release the execution right of the own host computer.

The execution right changing means 2 refers to the execution right storing means 1 and, if the own host computer has the execution right, rewrites the execution right to the "released state" and releases the execution right by the inter-host communication means 9. To other host computers.

On the other hand, if the own host computer does not have the execution right, nothing is done.

If the transaction can be executed, the transaction identification processing means 3 further determines whether or not the transaction requires exclusive processing (hereinafter referred to as "single host transaction") (step 24).

If it is determined in step 24 that the transaction is not a single host transaction, the transaction execution means 5 executes the transaction (step 27).

On the other hand, if it is determined in step 24 that the transaction is a single host transaction, the execution right checking means 4 is activated to check whether or not the own host computer has the execution right.

The execution right checking means 4 is the execution right storing means 1
To check which host computer has the execution right (step 25).

If it is determined in step 25 that the host computer has the execution right, the transaction execution means 5 executes the transaction (step 27).

On the other hand, when none of the host computers has the execution right, the execution right acquisition means 6 is activated to acquire the execution right (step 26).

The execution right acquisition means 6 activates the execution right changing means 2 and rewrites the execution right stored in the execution right storage means 1 so as to become the own host computer. Notify other host computers that the execution right has been acquired. However, at this time, if another host computer has already acquired the execution right, the necessary information is shared by the shared storage means 10 so that the transaction can be executed by the other host computer.
(Step 23).

When the execution right is acquired, the transaction execution means 5 executes the transaction (step 27). Even if another host computer has the execution right, the necessary information is stored in the shared storage means 10 so that the transaction can be executed by the other host computer (step 23). Also, if necessary,
The inter-host communication means 9 notifies other host computers that the transaction has been stored in the shared storage means 10.

Further, the other host monitoring means 8 notifies all the other host computers of the information that the own host is operating by the inter-host communication means 9 at regular intervals in all the host computers.

The host computer, which has not received this notification for a predetermined time or more, considers it to be down, and the execution right changing means 2 stores it in the execution right storing means 1 which is considered to be down. Disable the execute right. This predetermined time may be the above-mentioned fixed time or an arbitrary time.

Further, when the inter-host communication means 9 receives a notification of acquisition or release of the execution right from another host computer, the execution right changing means 2 rewrites the execution right information in the execution right storage means 1. Therefore, the execution right is managed.

In the embodiment of the present invention, the execution right check means 4 checks the execution right as described above, and the transaction can be executed by only one host computer. It has the advantage that it can be migrated without changing the program when migrating to the system.

The other host monitoring means 8 monitors the status of other host computers to detect the down of the host computer having the execution right, and the execution right changing means 2 changes the host computer having the execution right. Therefore, improvement of operability, which is a characteristic of the cluster system, can be expected.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described in detail with reference to the drawings in order to explain the above-described embodiment of the present invention in more detail.

FIG. 3 is a diagram showing an example in which the above-described embodiment of the present invention is applied to an inventory management system.

For example, consider an inventory management system including two host computers, host computers 3A and 3B, and terminals C1 and C2 as transaction input means.

Two host computers 3A and 3B
Share a database 310a and a transaction storage file 310b.

As shown in FIG. 4, an example of the database 310a includes a product name 41 and a quantity 42.

Transaction information storage file 3
An example of 10b is, as shown in FIG.
2 and entry / exit information 53.

The execution right possessing host computer information stored in the execution right possessing means 31A and 31B is initially set so that there is no execution right possessing host computer. Here, consider a case where a single host transaction in which ten product names “aaa” are delivered from the terminal C1 to the host computer 3A.

With respect to the input transaction, the transaction identification processing means 33A checks whether or not the transaction can be executed. Then, if the transaction is executable, it is checked whether it is a single host transaction, and since it is a single host transaction, the execution right checking means 34A is activated.

The execution right checking means 34A of the host computer 3A refers to the execution right storing means 31A to check which host computer has the execution right.

Since it is the first transaction, no host computer has the execution right.

Therefore, the host computer 3A activates the execution right acquisition means 36A. Execution right acquisition means 36A
Activates the execution right changing means 32A, and executes the execution right storing means 3
The execution right stored in 1A is rewritten to be the host computer 3A, and the inter-host communication means 39A notifies the other host computer 3B that the execution right has been acquired.

Here, the inter-host communication means 39B of the host computer 3B is activated, and the host computer 3A
Since it has been notified that the execution right has been acquired, the execution right changing means 32B is activated, and the execution right holding host computer stored in the execution right storing means 31B is rewritten so as to be the host computer 3A.

In the host computer 3A, since the execution right has been acquired, the transaction executing means 35A executes the transaction.

This transaction has a product name "aaa".
Is a transaction in which 10 items are stored, the record with the product name “aaa” is first read from the database 310a. At that time, the stock of product name "aaa" is 1
Since it is 00 pieces, if 10 pieces are put out from here, it becomes 90 pieces, and this is written back to the database.

At this point, the inventory of the product name "aaa" in the database 310a is 90 pieces.

Further, from the terminal C1 to the host computer 3A, a single host transaction for storing 30 product names "aaa" is input, and at the same time, from the terminal C2 to the host computer 3B, 10 product names "aaa" are stored. Consider the case where a single host transaction is entered.

In the host computer 3A, the input transaction is transaction identification processing means 3
At 3A, it is checked whether the transaction can be executed. If it is executable, it is checked whether or not it is a single host transaction. Since it is a single host transaction, the execution right checking means 34A is activated.

The execution right checking means 34A refers to the execution right storing means 31A to check which host computer has the execution right. At this time, since the execution right is held by the host computer 3A, the transaction execution means 35A executes the transaction.

This transaction has a product name "aaa".
Since the transaction is such that 30 items are delivered, first, the record of the product name “aaa” is read from the database 310a. At that time, the stock of product name “aaa” is 9
Since there are 0 pieces, if 30 pieces are delivered from here, it will become 60 pieces, which will be written back to the database.

At this point, the inventory of the product name aaa in the database 310a is 60 pieces.

On the other hand, in the host computer 3B, the input transaction is checked by the transaction identification processing means 33B whether or not the transaction can be executed. If it is executable, it is checked whether or not it is a single host transaction. Since it is a single host transaction, the execution right checking means 34B is activated.

The execution right checking means 34B refers to the execution right storing means 31B to check which host computer has the execution right. At this time, since the execution right is held by the host computer 3A, the information necessary for executing the transaction is stored in the transaction information storage file 310b, and the other host computer (host computer 3
It notifies 3A) from the viewpoint of B that the transaction information is stored in the transaction information storage file 310b.

In the host computer 3A, the other host computer 3B transfers the transaction information to the transaction information storage file 3 by the inter-host communication means 39A.
Upon receiving the information stored in 10b, the transaction execution means 35A reads out and executes the transaction information stored in the transaction information storage file 310b.

This transaction is executed under the product name "aaa".
Is a transaction in which 10 items are stored, first, the record of the product name “aaa” is read from the database 310a. Since the stock of the product name “aaa” is 60 pieces, if 10 pieces are stored from here, it becomes 70 pieces, which is written back to the database.

At this point, the inventory of the product name "aaa" in the database 310a is 70 pieces.

Now, let us consider a case where the user program does not perform the exclusive processing of the database and the above-mentioned two transactions are executed at the same time.

First, in the host computer 3A, since a transaction for shipping 30 product names "aaa" has been input, the product name "aaa" is input from the database 310a.
Read the record. The inventory at this time is 90 pieces.

On the other hand, since a transaction for storing 10 product names "aaa" is input to the host computer 3B, the product name "a" is stored in the database 310a.
The record of “aa” is read. The inventory at this time is still 90 pieces.

In the host computer 3A, the product name "aa
The inventory of "a" is 90, so if 30 are shipped from here, it will be 60, and this will be written back to the database.
At the same time, in the host computer 3B, the product name "aaa"
The stock of 90 is 90, so if 10 is stored from here, it will be 100, and this will be written back to the database.

As a result, the correct value on the database is 7
Although it should be 0, the actual value is 100, and it is clear that the correct result cannot be obtained without the database exclusive processing.

Further, the other host monitoring means 38A and 3
8B periodically provides information indicating that the host computer is operating. By exchanging by the inter-host communication means 39A and 39B, and this information is not notified for a certain period of time, it is possible to detect the down of another host computer.

That is, the host computer 3B can detect the down of the host computer 3A, acquire the execution right, and substitute the transaction processing by not receiving the notification from the host computer 3A having the execution right for a certain period of time.

[0070]

As described above, in the transaction exclusion method in the cluster system according to the present invention, since the transaction can be executed only by the host computer having the execution right, the user program is provided with an exclusive control mechanism. It has the advantage that it does not need to be incorporated.

Further, according to the present invention, by monitoring the status of another host computer, detecting the down of the host computer having the execution right and changing the execution right to the other host computer, the cluster system It can be expected to improve operability / reliability, which is a characteristic.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 3 is a block diagram showing an embodiment of the present invention.

FIG. 4 is a diagram for explaining the embodiment of the present invention and is a diagram showing an example of a database.

FIG. 5 is a diagram for explaining the embodiment of the present invention and is a diagram showing an example of a transaction information storage file.

[Explanation of symbols]

 1 Execution Right Storage Means 2 Execution Right Changing Means 3 Transaction Identification Processing Means 4 Execution Right Checking Means 5 Transaction Execution Means 6 Execution Right Acquiring Means 7 Execution Right Releasing Means 8 Other Host Monitoring Means 9 Inter-Host Communication Means 10 Shared Storage Means A Host Computer B Host computer C Transaction input means

Claims (3)

[Claims] 1. A system comprising a plurality of host computers,
The plurality of host computers share a database,
In a cluster system that performs online transaction processing, changes information about an execution right storage unit that stores which host computer has the execution right and information about the host computer that holds the execution right stored in the execution right storage unit Applicable to the execution right changing unit, the transaction identification processing unit for identifying the transaction input from the transaction input unit, and the transaction identified by the transaction identification processing unit to be processed by a single host computer. Execution right checking means for checking whether or not the host computer has the execution right by referring to the execution right storing means, and executing the transaction when the host computer has the execution right by the execution right checking means When there is no host computer that has acquired the execution right at the time of checking the execution right check means, the execution right acquisition means that acquires the execution right and the transaction identification processing means cannot execute the execution. Execution right release means for releasing the execution right when it is judged as a valid transaction, another host monitoring means for monitoring whether or not another host computer is operating, and inter-host communication for data transfer between host computers A transaction exclusive control method including a means and a shared storage means for storing transaction information and the like. 2. A host computer comprising a plurality of host computers,
The plurality of host computers share a database,
In a cluster system that performs online transaction processing, one host computer that has the execution right for the input transaction is determined, and a single-task transaction is performed only in the determined one host computer. Controlling that the single task transaction is started up and the database is accessed, and the single task transaction is not simultaneously executed by another host computer in the cluster during the database access. Exclusive transaction control method. 3. Each of the host computers includes a monitoring means of another host for monitoring whether or not another host computer in the cluster is operating, and an inter-host communication means for transferring data between the host computers. The transaction exclusive control method according to claim 2, wherein