JP2629330B2 - Data update commit processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding commit processing for data preservation in the case of a plurality of data updates that would otherwise cause inconsistency if not performed simultaneously, a resource management unit that performs commit processing in cooperation with a computer Aiming at a data update commit processing method capable of reducing communication overhead with a coordinator, the method includes a resource management unit for managing each data resource such as a database and a file, and a coordinator for managing a transaction executed by an application program. A computer system in which a plurality of data updates of the data resource by the transaction are collectively validated by a commit process executed by the coordinator requesting the resource management unit at the end of each transaction. The resource management unit The transaction program processes an open processing request of the data resource executed before the start of the transaction, and notifies the coordinator of necessary control information on the commit processing of the opened data resource. Each time a data update request for a resource is processed, the resource management unit notifies the coordinator of an update notification indicating the execution of the processing, and the coordinator determines, for the data resource corresponding to the received update notification, The resource management unit is requested to perform the commit process according to control information.

[Industrial applications]

The present invention relates to a data update commit processing method for maintaining data in a case of a plurality of data updates that would cause inconsistency if not performed simultaneously in a computer.

[Conventional technology]

FIG. 2 is a block diagram showing a configuration example of a computer system. The application program 1 requests so-called open processing for initializing control information for accessing necessary files and data resources such as a database by instructions such as open FILE and open DB as illustrated in the figure. Thereafter, a transaction for performing processing for accessing them is started by, for example, a begin TRN instruction.

Here, a transaction is a unit of processing provided for the purpose of controlling the processing of a plurality of data resources that would cause inconsistency unless data is updated at the same time so that inconsistency does not occur. When there are a plurality of data updates that need to be updated collectively in order to guarantee consistency between a plurality of data, those data updates are combined into one transaction, and the data resources prepared by the above-mentioned open instruction are collected. Of the necessary items, wr as shown
It is configured to issue a COMMIT instruction after requesting an update with ite FILE, write DB, etc.

The command issued by the application program 1 for requesting the processing of the data resources includes the resource management units 2a and 2b.
Open FILE and ope
The n DB instruction is processed by the initialization unit 10 of the resource management units 2a and 2b,
It performs initialization processing for acquiring a buffer and accessing a file or the like, and processes write FILE, write DB, and the like as described later.

Further, a coordinator 3 is provided to manage a transaction and support a commit request of the transaction. When the transaction start unit 16 receives a begin TRN instruction issued by the application program 1, a management table area for the transaction is created. Initialize and prepare the management table chain 19 described later.

Next, the write FILE and write DB instructions are received by the initial update processing unit 11 such as the resource management units 2a and 2b if they are the first update requests in the transaction for each data resource.

The first update processing unit 11 first sends the management table processing unit 17 of the coordinator 3 to the temporary update processing unit 13, the commit processing unit 14, and the recovery processing unit 15 as control information necessary for the subsequent commit processing. Each address when processing is requested and a data resource name such as a file name to be updated are notified, then the buffer is cleared, the updated data is stored in the buffer, and the update processing is completed. Thus, in each write instruction,
It does not actually update the data resources, but only buffers the updated data.

For the second or subsequent update request in the transaction, the update processing unit 12 accepts the request and does not notify the control information, but performs only the update processing as described above.

The management table processing unit 17 of the coordinator 3 creates a management table including the address and the data resource name received as the control information of the commit processing as illustrated in FIG. Connect and hold.

When a series of transaction processing is completed as described above, the application program 1 issues a COMMIT instruction to the coordinator 3 to request a commit processing. Therefore, the commit request processing unit 18 stores the transaction in the management table chain 19 of the transaction. The temporary update processing unit 13 of the resource management units 2a and 2b is requested to perform a temporary update process for each data resource indicated in each management table.

The provisional update processing unit 13 is configured to update each data resource 4 such as a file or a database in accordance with the update content held in the buffer.
While the original data is stored in a and 4b, these data blocks are provisionally updated in such a way that duplicated data blocks are provided, and the end state of the provisional update of each data is committed. Answer to Part 18.

The commit request processing unit 18 waits for a response of the end state of the provisional update, and upon receiving all the responses to the effect that the provisional update corresponding to all the management tables of the management table chain 19 has been completed normally, when the resources management units 2a and 2b It requests the commit processing unit 14 to perform commit processing.

Thus, the commit processing unit 14 updates the data resources 4a, 4b and the like provisionally updated as described above, for example, by deleting the original data block before the update and making the data block of the updated data valid. Complete.

In the commit request processing unit 18 of the coordinator 3,
After issuing the provisional update processing request as described above, if it is detected that the provisional update processing is not completed normally even for some of the provisional updates, the resource management unit 2a, Since the recovery processing unit 15 requests the recovery processing unit 15 to perform recovery processing and notifies the application program 1 that the processing has been stopped due to the update failure, the recovery processing unit 15 cancels all temporary updates of the data resources 4a and 4b.
Restore the original state without updating.

[Problems to be solved by the invention]

As is clear from the above description, the coordinator 3 has the necessary resource management units 2a and 2b to process the comic request.
From the temporary update processing unit 13, the commit processing unit 14, and the recovery processing unit
It is necessary to receive notification of control information such as each address and the name of the data resource to be updated when requesting the processing to 15. The data to be updated is determined by the application program 1 in which an update request instruction is issued and determined. Each time the first data update request in each transaction in the application program 1 is performed, the control information related to the required update data is operated from the resource management units 2a and 2b to the coordinator 3.

However, the processing in one application program is often divided into a large number of transactions, and by transmitting and receiving the control information for each transaction having data update processing as described above, the control information for commit is transmitted. There is a problem that communication causes a relatively large overhead.

An object of the present invention is to provide a data update commit processing method that can reduce communication overhead and the like between a resource management unit and a coordinator that perform commit processing in cooperation as described above.

[Means for solving the problem]

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

The figure shows the configuration of the computer system. Reference numerals 22a and 22b denote an initialization unit 30, an initial update processing unit 31, an update processing unit 12, and a temporary update unit that manage the data resources 4a and 4b in response to a request from the application program 1 and the coordinator 23. A resource management unit including a processing unit 13, a commit processing unit 14, and a recovery processing unit 15. The coordinator 23 includes a transaction start unit 32, a management table generation unit 33, a management table setting unit 34, a commit processing unit 35, and a management table chain 36. Manages the transaction of the application program 1 by the resource management unit 22
a, 22b to process the commit request.

[Action]

In the computer system, a resource management unit 22 that manages data resources 4a and 4b such as databases and files.
a, 22b, and the coordinator 23 that manages the transactions executed by the application program 1, the coordinator 23 at the end of each transaction.
Is requested by the resource management units 22a and 22b to be executed, and
Activate multiple data updates a and 4b collectively.

The resource management units 22a and 22b process open processing requests of the data resources 4a and 4b executed by the application program 1 before the start of a transaction, and provide necessary coordinator control information on commit processing of the opened data resources 4a and 4b. 23, and each time a data update request for the data resources 4a, 4b is processed by a transaction,
Since the resource management units 22a and 22b notify the coordinator 23, when the coordinator 23 processes the commit request, the data resource 4 corresponding to the received update notification
Only for a and 4b, the above-mentioned commit processing is requested to the resource management units 22a and 22b according to the corresponding control information.

According to the above processing method, complete control information on commit processing is notified only once at the time of opening a data resource at the beginning of an application program. Since the notification can be reduced to only the address or the like, the communication overhead for the commit process is reduced.

〔Example〕

In FIG. 1, portions denoted by the same reference numerals as those in FIG. 2 have the same functions as those of the related art, and include an initialization unit 30, an initial update processing unit 31, a transaction start unit 32, and a commit request processing unit 35. Are the same as the conventional initialization unit 10, initial update processing unit 11, transaction start unit 16 and commit request processing unit 18, respectively, except as described below.

In the computer system shown in FIG. 1, the application program 1 includes an open FILE instruction and an open DB
Initialize control information for accessing necessary data resources such as files and databases by instructions, etc.
After requesting so-called open processing, a transaction for performing processing for accessing them is started by, for example, a begin TRN instruction, and, among the data resources prepared by the open instruction, a necessary one of a write FILE instruction as shown in FIG.
After requesting an update with a write DB instruction or the like, a COMMIT instruction is issued at the end of a series of processing.

The open FILE and open DB instructions are processed by the initialization unit 30 of the resource management units 22a and 22b to execute initialization processing for accessing data resources as in the related art, and to the coordinator 23 according to the present invention. On the other hand, as the control information for the commit processing of the data resource to be opened, the addresses of the temporary update processing unit 13, the commit processing unit 14, and the recovery processing unit 15 and the name of the opened data resource are notified.

The management table generation unit 33 of the coordinator 23 receives the control information, generates a management table as illustrated in FIG. 3B for holding the control information of each opened data resource, and the like. The connection is made to the chain 36, and the management table address is passed to the resource management units 22a and 22b, for example.

Next, begin issued by application program 1
Transaction start part 3 of coordinator 23 with TRN instruction
When 2 is accepted, the item of the update display of each management table of the management table chain 36 for the transaction (see FIG. 3B) is initialized to the display of "not updated".

In the started transaction, write FILE, write
When a data update request such as a DB instruction is issued, if it is the first update request in this transaction for each data resource, the first update processing unit 31 such as the resource management units 22a and 22b
Received, and notifies the management table setting unit 34 of the coordinator 23 of the management table address corresponding to the data resource name as an update notification for notifying that the update request is to be processed. Perform the update process only with

The management table setting unit 34 sets the display of “update” in the update display section of the management table based on the management table address received in the update notification.

For each data resource, for the second or subsequent update request in the transaction, the update processing unit 12 accepts the update request and performs only the update processing as described above.

The application program 1 completes a series of transaction processing, and issues a COMMIT instruction to the coordinator 23.
Issue a request for commit processing, the commit request processing module 35 will update the management table of the management table chain 36 according to the contents of all the management tables only in the management table where the item of update display is displayed as "update". The temporary update processing is requested to the temporary update processing unit 13 of the resource management units 22a and 22b.

The provisional update processing unit 13 performs the provisional update of the data resource in the same manner as in the related art, and returns an end state. When the commit request processing unit 35 receives all the responses of the normal completion of the temporary update corresponding to all the management tables in the management table chain 36 corresponding to “update”, the commit request processing unit 35 performs the commit processing to the commit processing unit 14 of the resource management units 22a and 22b. And complete the main update of the data as in the prior art.

If the commit request processing unit 35 detects that even a partial update is not completed normally, the recovery processing of the resource management units 22a and 22b is performed for all the data resources that have requested the temporary update process. A request is made to the unit 15 for recovery processing, and all the provisional updates are canceled to restore the original state where no updates are made.

According to the above-described processing method, for each piece of control information required for the commit process, each transaction simply needs to initialize and set the update display of the management table, so that the communication overhead between the coordinator and the resource management unit related to the commit process is reduced. can do.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in a commit process for data preservation in the case of performing a plurality of data updates that would cause inconsistency if not performed simultaneously by the computer, the commit process is performed in a coordinated manner. There is a remarkable industrial effect that the processing overhead of the system can be improved by reducing the communication overhead and the like between the resource management unit and the coordinator.

[Brief description of the drawings]

 FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a block diagram showing a conventional configuration example, and FIG. 3 is an explanatory diagram of a management table. In the figure, 1 is an application program, 2a, 2b, 22a and 22b are resource management units, 3 and 23 are coordinators, 4a and 4b are data resources, 10, 30 are initialization units, 11, 31 are initial update processing units, 12 is an update processing unit, 13 is a temporary update processing unit, 14 is a commit processing unit, 15 is a recovery processing unit, 16 and 32 are transaction start units, 17 is a management table processing unit, 18, and 35 are commit request processing units, 19 , 36 is a management table chain, 33 is a management table generation unit, and 34 is a management table setting unit.

Claims (1)

(57) [Claims] A resource management unit (22a, 22b) for managing each data resource (4a, 4b) such as a database and a file.
And a coordinator (23) for managing transactions executed by the application program (1)
And a commit process executed by the coordinator requesting the resource management unit at the end of each transaction to collectively validate a plurality of data updates of the data resource by the transaction. In the system, the resource management unit (22a, 22b) processes an open processing request of the data resource executed by the application program (1) before the start of the transaction, and executes the commit of the opened data resource. The coordinator (23) is notified of necessary control information on processing, and each time a transaction updates a data update request for the data resource, an update notification indicating the execution of the processing is sent to the resource management unit (22a, 22b). ) Notifies the coordinator (23), and the coordinator (23) A data update commit processing method configured to request the resource management unit (22a, 22b) to perform the commit processing according to the control information (36) for the data resource corresponding to the update notification. .