JP2650907B2 - Resource synchronization control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resource synchronization control system for a data processing system, and more particularly to a resource synchronization control system suitable for performing data synchronization in a distributed database system.

[Conventional technology]

A conventional synchronous control method at the end of a transaction of data processing for a plurality of resource groups is disclosed in Japanese Patent Application Laid-Open No. 58-163022. (Synchronous processing) is divided into two processing phases. Specifically, in the update assurance processing (first phase), confirmation of synchronization is obtained, confirmation is made that all resources can be synchronized, and the end of transaction processing is notified in synchronization end processing (second phase). To complete the synchronization. Therefore, communication between the processing systems is required for each phase. However, if one of the resources of the plurality of databases has not been updated, or if only one of the resources has been updated, the resources of the other database systems are not updated. Since there is no need to ensure consistency, there is no need to perform the first phase update assurance processing for obtaining confirmation of the synchronization processing.

Performing synchronous processing when transaction processing is performed across a processing system that manages multiple databases in this way ensures that a series of transaction processing has been reliably performed in each database processing system. This is to prevent a state in which the processing has not been completed in any of the database processing systems.

[Problems to be solved by the invention]

In the above-described conventional technology, the synchronization process at the end of a transaction achieves synchronization completion by notifying two processes (phases), that is, an update assurance process (first phase) for obtaining confirmation of synchronization and a completion of the transaction process. End processing (second phase) that does not take into account the reduction of the number of communications in each phase for the processing system of each database (resource management).
When the processing systems of each database are distributed, the communication load increases, the time required for transaction processing increases, and the time required for occupying the resources of the database processing system also increases. There is a problem that has an adverse effect on the processing of.

An object of the present invention is to provide a resource synchronization control method for reducing the number of communications between the processing systems of each database with respect to the resources of the database processing system at the end of a transaction without impairing the guarantee of the consistency of the resources. To provide.

[Means for solving the problem]

The object of the present invention is to provide a resource group processing status bit string that manages whether or not an update process is being performed on each resource in a transaction process on each resource of the processing system of each database, and a resource group that has been updated. A resource group processing state management table including a resource group list holding the names of
Referring to the resource processing state management table, the resource group that has been updated is known from the resource group processing state bit string and the resource group list. When the processing is performed using only one resource, it is achieved by omitting the first phase of the synchronization processing including the first phase (update assurance processing) and the second phase (end processing).

[Action]

The resource synchronization control method according to the present invention is characterized in that, in a distributed database processing system, when an update process is performed on a resource of a processing system of each database in a transaction process, a resource group processing state bit string of a resource group processing state management table Bit is turned on, and the updated resource name is registered in the resource group list. At the end of the transaction processing, the resource group processing state management table is referred to. If the update processing has not been performed for all the resources, If
When the first phase (update assurance processing) is not performed on all resources, the second phase (end processing) is performed, and when the update processing is performed on only one resource, the update processing is performed. The second phase is performed on the resource, and after the second phase is completed normally, the second phase is performed on the other resources. If the update processing is performed on two or more resources, the updated resource is performed. Performs the first phase, and when the confirmation of the synchronization is obtained, the operation is performed to perform the second phase for all the resources. Therefore, it is possible to complete the transaction between a plurality of resources with minimum synchronization processing. is there.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. An example of the system configuration of the present invention is shown in FIG.
Each processing device has a CPU, a processing program, and a database management system (DBMS). Communication control between the processing devices is performed by an online control program of each processing device. Each processing device holds data in a disk device or the like and manages resources. A resource group processing status management table, which will be described later, is provided in the processing program of each processing device. In such a system configuration, an embodiment of the control method of the present invention will be described with reference to FIG. 1. When the processing device B operates to perform transaction processing, the control of the synchronization of the transaction in the control method is performed. It also functions as a management system to perform. The processing units A and C refer to data for resources A and C in the processing of the transaction generated by the processing unit B. This is a management system that manages requested processing such as updating.

FIG. 2B shows an outline of the contents of the resource group processing state management table for managing the processing state of the resource group. The resource group processing state management table is provided in the processing program of the processing device, and its contents include a variable number of resource groups, a bit string, and a processed resource group list.

Next, a process associated with the start of a transaction will be described with reference to FIG. 1A.
The resource group processing state management table is initialized, and a transaction is started (1). Then, the processing apparatus B refers to the data with respect to the processing apparatus A. When requesting an update process, particularly when requesting the processing device A to perform a data update process (3), an update flag of the resource group processing status management table in the processing device B is first set (2). Thereafter, it is inquired whether or not the update processing is involved, and when it is reported that the update processing is involved, the update flag is set once again according to the report (4). The logical AND of the flag bit set before the update processing and the flag bit set after the update processing is calculated in the resource group processing state management table, and the update flag is set for the resource in the update processing state. Similarly, the same processing of (5), (6), and (7) is performed on the processing apparatus C, and the same processing of (8) and (9) is performed on the processing apparatus B, which is its own management system. The processing is performed, and the processing state of the resource group is managed. FIG. 2 shows a flowchart of the processing for managing the update processing state for the above resources.

This resource processing will be described with reference to the flowchart of FIG. 2A. In the transaction processing, when data update processing is requested for each resource, an update check is performed. If it is updatable (1
1) Turn on the update bit for the resource group processing status management table in the processing device B (12). When the update process is performed on the resource, an inquiry is made as to whether the process is related to the update process. If the inquiry is reported to be a process related to the update process (13), the processing device The update bit of the resource group processing state management table in B is newly turned on, and the above-mentioned update bit when there is a possibility of update and the update bit when there is a report are performed (14), and true During the update process, the bit string of the number of resource groups in the resource group processing state management table is turned on for the resource group, and the updating process is being managed by the resource group processing state management table.

In this way, the update state management processing for the resources in FIG. 2A is performed, and the transaction end processing (10) in FIG. 1A is performed.
Is started, the processing unit B of the resource B refers to the resource group processing state management table shown in FIG. 2B, controls the synchronous processing according to the processing state of each resource, and Controls transaction end processing based on the number of communications. FIG. 3 shows the flow of the above-described synchronization processing. That is, in FIG. 1, the update state is managed, the result is held in the resource group processing state management table, and the synchronization control processing is described using the table.
FIG.

FIG. 3 manages transaction processing, and performs the following end synchronization processing in transaction end processing. Referring to the bit string of the number of resource groups in the resource group processing state management table, check whether all bits are off (15). If all bits are off, it is determined that no update processing has been performed, and each processing is performed. A synchronization end process C (second phase) for notifying the device of the end of the transaction is performed (22). Next, it is checked whether only one bit is on (16). If only one bit is on, the processing of the resource group processing state management table is performed by the resource group list for the processing device having the bit-on resource. Synchronization end processing C (second phase) is performed, and if it is not rollback (18), synchronization end processing C (second phase) is performed on the processing device of another resource (19). As described above, when all the bits are off or only one bit is on, the update processing has not been performed by another resource, so that the completion of the update processing is confirmed and the synchronization processing is confirmed. No action is required. When a plurality of bits are turned on, the first processing unit manages each bit-on resource.
An update assurance process Pr-C, which is a phase synchronization process, is performed (20), and if it is not rollback (21), a synchronization end process C (second phase) is performed for each processing device (22).

As described above, synchronization processing according to the processing state is performed,
All processes related to the transaction are completed.

Next, FIG. 1B shows an example of control according to the processing state of each resource for the processing associated with the end of a transaction, with reference to FIG. 1B.

X1 is an example of the case where the maximum number of communications is reached in this transaction processing. In this example, when the update processing is performed on all three resources, the update assurance processing (Pr- C) is performed for each of the three processing devices. If confirmation cannot be obtained from all management systems, for example, if any of the resources that have undergone the update process are locked and become blocked, Update process has not been completed,
Even if the update assurance process (Pr-C) is performed, confirmation of the synchronization process cannot be obtained. Further, there is a case where the updating process is not completed even if the updating process is simply performed. In such a case, the processing unit of each resource is returned to the transaction start state by the rollback processing. When all the confirmations are obtained, the second phase synchronization end (C) for notifying the end of the transaction processing is performed for each processing device, and all the processing related to the transaction is ended.

X3 and Xn are examples in which the minimum number of communications is performed in the transaction processing. In this example, only one resource is updated or all resources are not updated. In the former case, the completion of the update process is confirmed for a resource group other than the resource for which the update process has been performed. However, the first-phase processing for obtaining confirmation of the synchronization processing can be omitted. First, synchronization of the updated resources with respect to the processing devices is completed (C), and if the processing is not successful, rollback is performed for all the processing devices. If the processing has succeeded, a synchronization end process (C) is performed on the remaining processing devices, and all processes related to the transaction are ended. Also in the latter case, since the update process has not been performed, the first phase for confirming the completion of the update process for the resource group and obtaining confirmation of the synchronization process can be omitted. Therefore, only the synchronization end processing (C) is performed for each resource.

X2 is an example of a case where, in this transaction processing, a search process is performed on the processing device A of the resource A, and an update process is performed on the processing device of another resource.
In this example, the synchronization processing in the first phase is not performed for the resource processing device for which only the search process has been performed, and the synchronization process is not divided for the resource processing device for which the update process has been performed. The update assurance process (Pr-C), which is a process, is performed, and after confirmation is obtained, a second phase synchronization end process for notifying the end of the transaction process and a synchronization end process for the processing device A are performed.

According to the present embodiment, at the end of the transaction, the resource group processing state management table is referred to, and the resource group processing state bit sequence and the resource group list in the table relate to the update processing state and update processing of the resources of each database. When the resource name is checked and the update process is not performed or the update process is performed only in one resource group, the first phase for obtaining confirmation of synchronization is omitted, and the number of communications between the processing systems of each database is omitted. , The transaction processing can be surely terminated, and there is an effect that resource synchronization control can be performed efficiently.

Further, when a transaction is processed using a processing system of a plurality of databases as in the present embodiment, the above-described efficient synchronous processing is performed.
Even in the case where there is a processing device that has not completed the data update process, consistency between the processing devices of a plurality of resources can be achieved without erroneously terminating the transaction.

〔The invention's effect〕

According to the present invention, when a transaction is processed across a plurality of resources, the resource group processing state management table allows an optimum synchronization process in the synchronization control for surely terminating the transaction process on each resource. By performing the processing for each resource processing system, the number of communications is reduced, and there is an effect that a more efficient data processing method is realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a transaction process for a plurality of resources according to an embodiment of the present invention, FIG. 2 is a flow chart at the time of processing on the resources of FIG. 1, and FIG. FIG. 4 is a flowchart showing a correspondence table between processing on resources and transaction end processing, and FIG. 5 is a block diagram of a system according to the present invention. 1-9 ...... data processing, 10 ...... transaction termination processing, the synchronization process in the 15 to 22 ...... integrity control, the pattern of the synchronization processing example in the X ₁ to X _n ...... consistency control.

Claims (1)

(57) [Claims] In a distributed database system having a plurality of data resources, a table for managing the status of update processing for each resource is provided in the system, and when a request for update processing of data resources is made in transaction processing. In the table, the fact that the update process is being executed for the data resource is registered in the table, and at the end of the transaction process, the state of the update process managed by the table is referred to, and the update process is performed in all the resources. If not, a synchronization termination process is performed for all the data resources to complete the synchronization. If only one data resource is updated, the update process is performed. First, a synchronization end process is performed on the data resource that has been Data synchronization is performed on the data resources, and if the update processing is performed on two or more data resources, the update is obtained to confirm the synchronization of the updated data resources. A resource synchronization control method comprising: performing a guarantee process; and performing a synchronization termination process on all data resources when synchronization is confirmed.