JPH0447344A - History journal recording system - Google Patents

Abstract

PURPOSE:To attain the efficient recording of a history journal and the shortening of restoring time at the time of the update of data by outputting only minimum information necessary for restoring the fault of a medium from a recording area recorded temporarily. CONSTITUTION:The latest update position information 3-1-2 recorded in the recording area 3-1 is read, and a position information file 3-3 is retrieved, and when that position information does not exist, the update position information 3-1-2 is stored in the position information file 3-3, and further, the update position information 3-1-2 and post-update contents 3-1-1 are recorded in the history journal 3-2. Next, the second update position information 3-1-4 from the end recorded in the recording area 3-1 is read, and the position information file 3-3 is retrieved, but in this case, since the same information as the position information is stored before, this update information is not outputted to the journal 3-2, and the processing of the third update information from the end of the recording area 3-1 is executed. Thus, the information in the history journal is minimized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the recording of data recovery information from a media failure when updating data in an information processing system, and in particular enables efficient recording and shortening of recovery time. Regarding the history journal recording method.

[Conventional technology]

Since it is impossible to recover a database or file from a media failure from the medium at the time of the failure, as shown in Figure 4, the database or file must be saved from the save 4-3 immediately before the data update process. , and then use the history journal 4-2 recorded during the data update process to recover the state immediately before the media failure occurred m4-
Processing to return to 5 is performed.

Conventionally, in this history journal recording method, location information of updated databases, etc., and updated contents are additionally recorded in the history journal in sequence every time a new update occurs.

[Problem to be solved by the invention]

The conventional history journal recording method only records the updated information each time there is an update, so if there are a large number of updated data 2, a large amount of history journals will be required. At the time of recovery, all update information from the beginning to the end of the large amount of history journals is used for the recovery process, which has the disadvantage that it takes a long time to recover.

[Means to solve the problem]

The structure of the history journal recording method of the present invention includes a sequential recording section that sequentially records database and file update information in a recording area, and a recording area conversion that switches the recording area to another recording area based on the amount of recorded information. an instruction unit, a final valid information search unit that searches the database and file update information recorded in the recording area to obtain only the final valid information, and a journal record that records the final valid information obtained in the above into a history journal. and an information output unit that outputs the amount of input database and update information and the amount of history journal recording.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

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

In the figure, the sequential recording unit 1-3 records the contents updated by the update program 1-1 in the database 1-2.
The updated position information is sequentially recorded in the recording area (A) 1-5 or the recording area (B> 1-6).

When the update information recorded in the recording area (A) 1-5 or the recording area (B) 1-6 occupies a certain percentage of the recording area, the recording area conversion instruction unit 1-4 converts the output to one side. It instructs to switch to the recording area of 1, and further instructs execution of the final valid information search unit for the recording area that has reached the standard value.

The final valid information search unit 1-8 performs the following for the recording area:
The final update result for each position information of the database in the recording area is obtained and outputted to the journal recording units 1 to 9.

The journal recording unit 1-9 outputs the last update information obtained above to the history journal 1-12.

The information output unit 1-10 records the amount of input update information and the amount recorded in the history journal 1-12 in a log file 1.
-11.

Next, the operation will be explained based on FIG.

FIG. 2 is a diagram for explaining the history journal recording operation in one embodiment of the present invention.

When the update program 1-1 updates the database 1-2, the updated information is sequentially input to the recording unit 1-3, and the updated position information and updated contents of the databases 1-2 are stored in the recording area (A) 1-5. Recorded sequentially.

■If the update information recorded in the recording area (A) 1-5 occupies a certain standard in that recording area, the recording area conversion instruction unit 1-4 detects this state and The recording section 13 is sequentially instructed to convert from the recording area (A) 1-5 to the recording area (B) 1-6. Furthermore, the recording area conversion instruction unit 1-4 converts the recorded recording area (A) 1
-5, the final valid information search unit 1-8 is activated.

■The final valid information search unit 1-8 is located in the recording area (A) 1-5.
The final update result for each database position information within the recording area (A) 15 is obtained and output to the history journal 1-10 through the journal recording section 1-9. Further, the information output unit 1-1O inputs the input number of update information items and the number of journal output items from the final valid information search unit 1-8 and the journal output unit 1-9,
Output to log file.

■Furthermore, when the update information sequentially recorded in the recording area (B) 1-6 occupies a predetermined proportion of the recording area, the recording destination is changed by the recording area conversion instruction unit 1-4 in the same way as in ■. The recording area (A>1-5) is switched again. At this time, the information recorded in the previous recording area (A) 15 is not saved, and only new information is sequentially recorded by the recording section 1-3.

■Similar to the previous ■, the final information search unit 1-8 obtains the final update result from the recording area (B) 1-6, and the journal recording unit 1-9 searches for the final update information recorded in the previous ■. Then record. Furthermore, the information output unit 1-10
The input number of update information items and the number of journal output items are input from the final valid information search unit 1-8 and journal output unit 1-9, and output to the log file.

FIG. 3 is a diagram for explaining the operation at the time of retrieving final valid information in one embodiment of the present invention.

(1) Read the last updated position information 3-1-2 recorded in the recording area 3-1, search the position information file 33, and if the position information does not exist, the position information file 3-3
The updated location information 3-1-2 is stored in the history journal 3-2, and the updated location information 3-1-2 and the updated content 3-1-1 are further recorded in the history journal 3-2.

(2) Next, read the second to last updated position information 3-1-4 recorded in the recording area 3-1 and search for the position information file 3-3, but in this case, the same position information as that The information has already been stored, but in this case, since the same information as the position information has already been stored, this update information is not output to the history journal 3-2, but is stored three times from the end of the recording area 3-1. Process the update information.

In this way, by reading the recording area 3-1 in order from the last update information and processing while ignoring the same update information as the position information that has already been output, the latest final valid information can be obtained for each position information.

By processing as described above, it is possible to suppress the information on the history journal to the necessary minimum.

Note that the present invention is not limited to the case where a file is used as the recording area 1-5 in FIG. 1, but also includes, for example, a system in which update information is temporarily stored in memory to shorten search time. Needless to say.

Similarly, it goes without saying that the present invention is not limited to the case where a file is used as the location information file 3-3 in FIG. 3, and includes, for example, a system that uses memory as a storage area.

〔Effect of the invention〕

As explained above, the present invention enables: - Outputting only the minimum information necessary for medium failure recovery from the temporally allocated recording area to the history journal, the history journal is updated when updating data in the information processing system; This has the effect of efficient recording and shortening recovery time.

The effects of the present invention are particularly significant in data update systems in which the same record in a database or file is updated many times.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram of an embodiment of the present invention, Fig. 2 is a diagram for explaining the history journal recording operation in this embodiment, and Fig. 3 is an illustration of the operation when retrieving the last valid information in this embodiment. FIG. 4 is a diagram for explaining a data recovery method in the event of a media failure. 1-1... Update program, 1-2... Database, 1-3... Sequential recording section, 1-4... Recording area conversion instruction section, 1-5... Recording area A, 1 -6...Recording area B, 1-7...Position information file, 1-8...
Final valid information retrieval section, 1-9... Journal recording section,
1-10... Information output unit, 1-11... Log file, 1-12... History journal, 2-1...
Recording area A, 2-2... Recording area B, 2-3... History journal, 3-1... Recording area, 3-2...
・History journal, 3-3... Location information file, 4-1... Database, 4-2... History journal, 4-3... Saving database etc. immediately before data update processing, 4- 4... Database immediately before data update processing, 4-5... Database in state immediately before a media failure occurred.

Claims (1)

[Claims] a sequential recording unit that sequentially records database and file update information in a recording area; a recording area conversion instruction unit that switches the recording area to another recording area based on the amount of recorded information; A last valid information search unit that searches database and file update information to obtain only the last valid information; a journal recording unit that records the last valid information obtained above in a history journal; and a journal recording unit that records the last valid information obtained above in a history journal; 1. A history journal recording method, comprising: an information output unit that outputs the amount and the recorded amount of the history journal.