JPH07191895A - Memory file backup method of transaction processing system - Google Patents

Abstract

PURPOSE:To provide the memory backup system for preventing the on-line processing of a transaction processing system from being interrupted and for shortening memory file recovery processing time at the time of restoration. CONSTITUTION:A transaction processing part 100 updates a memory 200 by recording a history record in a transaction history 300 synchronously with the updating of the memory 200. When fixed time or a certain number of transactions are processed, a transaction history extracting part 410 extracts the history record from the transaction history 300. The extracted history record is updated into the same image as the memory 200, which is updated by the transaction processing part 100, in a backup file 500 on a nonvolatile storage medium by a backup file updating part 420. At the time of any system fault, the fault is recovered by utilizing the backup file 500 and the transaction history 300.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory file backup method for a transaction processing system, and more particularly to a memory file backup method for a system that requires a large amount of transaction processing in a short time.

[0002]

2. Description of the Related Art In a transaction process of an online system, when a system down error such as power failure occurs in a system that updates a memory file resident in memory, the memory file resident in memory disappears. There is. Therefore, during normal operation, a backup method is generally used in which the history of transaction processing during system operation is recorded, and at the same time, the memory files recorded in the memory are saved to a nonvolatile storage medium at regular intervals. There is. When a system down failure such as power failure occurs, the above-mentioned conventional method is used to restore the memory to the state before the failure by using the information of the non-volatile storage medium in which the memory file is recorded and the transaction processing history. be able to.

Further, in the above-mentioned conventional method, the backup process of saving the memory file in the non-volatile storage medium becomes a bottleneck in the system performance. For the purpose of avoiding this bottleneck and shortening the recovery processing time in the event of a system failure, it is known to devise a method of selecting and backing up only the minimum necessary memory file information. According to Japanese Unexamined Patent Publication (A) No. 1-125631 “System Failure Recovery Method”, when a memory file is backed up, only the information of the memory file that has been updated since the last backup is selected and saved. However, the backup process is shortened by reducing the contents of the memory file.

[0004]

In the conventional memory file backup method, updating of the memory file must be prohibited during the process of writing the file resident in the memory to the nonvolatile storage medium, and the transaction during that period must be prohibited. The process is interrupted. This interruption is unavoidable in any of the conventional methods because the memory file information is directly transferred from the memory to the nonvolatile storage medium.

In the conventional method, the information in the memory file lost due to the system failure is re-developed in the memory by copying the copy backed up in the non-volatile medium.
Restore the transaction processing after the backup point by re-executing it based on the history.

Whether the transaction recorded in the history is a transaction that needs to be re-executed or not can be determined by prohibiting the update of the memory file information at the time of backup. That is, if the information update of all the memory files is prohibited from the start to the end of the backup, the transactions to be reprocessed for all the memory files are only the transactions after the information update prohibition.

Further, in the method of prohibiting the information update of each file of each memory file only from the start to the end of the backup of the file, the transaction to be reprocessed must be determined for each file.

Furthermore, in determining the reprocessing transaction, it is necessary to determine the range in which it is possible to uniquely determine whether or not the update by the transaction is completed for any transaction. At this time, the minimum unit of the range is a transfer unit to the non-volatile storage medium for backup, and the transfer unit means a file input / output unit of the non-volatile medium. Therefore, it is impossible to reduce the memory update inhibition time by the transaction processing beyond the limit value determined by the trade-off with the input / output processing efficiency. That is, in the conventional method, it is inevitable to interrupt the transaction processing for backup.

[0009]

An object of the present invention is to update a backup file of a memory file with history information recorded in a transaction history, and to backup the memory file in a nonvolatile storage medium without interrupting transaction processing. An object is to provide a memory file backup method for a transaction processing system that stores a copy.

Therefore, the memory file of the present invention and the backup file for restoring the memory file are
The transaction processing system that initializes to the same state at startup has a nonvolatile record of the history record consisting of the address of the memory to be updated and the memory image before and after the update when the memory file is updated by executing the transaction process. Processing unit for writing a history extraction command including a logical area number designating the logical area when the predetermined number of history records are written to the logical area During normal execution of transaction processing, the history extraction command is accepted, the history record of the logical area specified by the logical area number is acquired from the transaction history, the backup file is updated, and the status of the backup file is changed. Following the state of the memory file Alternatively, a backup process for extracting an unprocessed history record from the transaction history when updating the transaction process, updating the backup file with the history record, and restoring the backup file to the state immediately before the failure of the memory file. And a memory expansion unit that expands the backup file in a memory and restores the memory file.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

Referring to FIG. 1, which shows the system configuration of an embodiment of the present invention, a transaction processing system 10
Is a transaction processing unit 100, a memory 200 in which a memory file is expanded, a transaction history 300 recorded in a non-volatile storage medium, a backup processing unit 400 processing the history 300, and a backup file 500 recorded in the non-volatile storage medium. And a memory expansion unit 600 that expands the backup file in the memory 200.
And.

Referring to FIG. 2 showing respective configurations of the transaction processing unit 100 and the backup processing unit 400, the transaction processing unit 100 includes a transaction execution unit 110 and a history extraction instruction unit 120, and the backup processing unit 400 includes It has a transaction history extraction unit 410 and a backup file update unit 420.

The operation of the system 10 in this embodiment will be described with reference to FIG. 2 by classifying it into transaction processing, backup processing, and failure processing.

When executing transaction processing,
When the transaction processing unit 100 is executed, the transaction execution unit 110 synchronizes with the update of the memory file loaded in the memory 200, and the memory update information record including the update target memory address and the memory image before and after the update. To the transaction history 300. The information storage area of the non-volatile storage medium for recording the transaction history 300 is logically divided into a plurality of logical areas, and one logical area is further composed of a plurality of history records. The transaction execution unit 110
When the memory update information records are sequentially written in the transaction history 300 and the last memory update information record is written in the logical area, the history extraction instruction unit 120 is activated and the “history extraction instruction request” information history extraction instruction unit 120 is delivered.

The history extraction instruction section 120 activates the transaction history extraction section 410 based on the delivered "history extraction instruction request" information. The history extraction command 700 as the startup information includes the logical area number in the transaction history 300 whose history has been written.

Next, when executing the memory backup processing, the history extraction command 70 from the history extraction instruction unit 120 is executed.
0 is an activation command for the backup processing unit 400, and the history extraction command 700 is passed to the transaction history extraction unit 410. Transaction history extraction unit 410
On the basis of the history extraction command 700, sequentially reads the record group forming the logical area of the transaction history 300 and delivers it to the backup file update unit 420. The backup file update unit 420 executes the same update to the backup file 500 as that made to the memory 200 by the transaction execution unit 110 based on the transaction history information passed from the transaction history extraction unit 410.

At the time of initial startup of the system that performs transaction processing, the memory expansion unit 600 reads the storage information in the backup file 500 and reads the memory 20.
Store in 0. That is, at the time of initial startup, the contents of the memory 200 and the backup file 500 are the same, and all updates to the memory 200 by the transaction processing unit 110 after the initial startup are performed by the backup processing unit 400 via the transaction history 300. It is reflected in the backup file 500. As a result, the memory 200 and the backup file 500 can always hold the same information.

Further, when the failure restoration processing is executed, the information in the memory 200 is logically damaged due to the cause of the system stoppage due to the failure.

First, the transaction history extraction unit 410 of the backup processing unit 400 extracts all the stored information in the transaction history 300 that has not been extracted yet. That is, all the memory update information that has not been reflected in the backup file is extracted. The transaction history extraction unit 410 delivers the extracted information to the backup file update unit 420, and the backup file update unit 420 updates the backup file 500 based on the extracted information. Backup file 5
The content of the stored information of 00 is the same as that of the memory 200 immediately before the failure.
It will be the same as the content of the stored information of. Then, the memory expansion unit 600 reads the entire contents of the backup file 500 and copies the read information to the memory 200.

[0021]

As described above, according to the present invention, by utilizing the transaction history, it is possible to provide a backup method of a memory file prepared for a system failure without affecting transaction processing at all. it can.

Further, in a system that requires extremely high processing performance and updates memory resident information, it is inevitable that the memory file will increase, and memory access competition between transaction processing and memory backup processing will increase performance. It becomes a bottleneck. In such a system, according to the present invention, this memory backup method can completely avoid a memory access interruption that hinders the performance of transaction processing.

[Brief description of drawings]

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

FIG. 2 is a diagram showing the configuration of a transaction processing unit and a backup processing unit shown in FIG.

[Explanation of symbols]

 10 transaction processing system 100 transaction processing unit 110 transaction execution unit 120 history extraction instruction unit 200 memory 300 transaction history 400 backup processing unit 410 transaction history extraction unit 420 backup file update unit 500 backup file (nonvolatile medium) 600 memory expansion unit 700 history Extraction command

Claims (1)

[Claims] 1. A transaction processing system for initializing a memory file and a backup file for restoring the memory file to the same state at start-up, when a memory file is updated by execution of transaction processing, an update target memory When a history record consisting of the address of the memory and the memory image before and after the update is written to the logical area of the transaction history stored in the nonvolatile storage medium and a predetermined number of history records are written to the logical area, the logical area And a transaction processing unit that issues a history extraction command that includes a logical area number that specifies the logical area number that specifies the logical area number Get record and backup file Update, the state of the backup file is made to match the state of the memory file, or the unprocessed history record is extracted from the transaction history when the transaction process is restored, and the backup file is updated by the history record. A transaction processing unit that restores the backup file to a state immediately before the failure of the memory file, and a memory expansion unit that expands the backup file in a memory and restores the memory file. System memory file backup method.