JPS63217441A - Journal collecting system - Google Patents

Abstract

PURPOSE:To avoid omission of the journal codes up to the final check time point when a power supply is cut off by providing a flash file on a nonvolatile fast file device so that the journal images on a current journal buffer are written at a high speed to the flash file for each check point. CONSTITUTION:A flash file 71 uses a nonvolatile fast file device 7. A journal flash processing means 25 of a journal output process 5 outputs at a high speed the journal codes set on the journal buffers 41-4n to the file 71 for each check point for the replacement processing of a data file 31. In such a way, the omission (erasion) of the journal codes can be avoided up to the final check time point when a power supply is cut off.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a file device (for example, a magnetic disk device, etc.)
The present invention relates to a file recovery method using a journal in the event of a device or media failure, and particularly relates to a journal collection method when a power outage (stop 'r4) occurs.

[Conventional technology]

Conventionally, file recovery methods when a device or medium failure occurs in a file device include a method using a journal and a duplication method for each file or file device W (volume).

In the method that uses a journal, for file recovery, all backup images of data files are saved at regular intervals (for example, every morning), and the final checkpoint (updated image) of data files is always collected when data files are updated. An updated image (journal) up to the final checkpoint (among the checkpoints that are the logical completion points of the processing) is required.

On the other hand, in the method of duplicating data files in units of files or file devices (volumes), both the primary and secondary data files are updated at the same time. There is no need to collect journals when saving data or updating data files.

In the method of duplicating data files per file or file device (volume), there is no need to collect journals when updating data files, but twice the capacity is required for each data file or file device (volume). However, there is a disadvantage that the file size increases.

Therefore, a method using a journal is more commonly used as a file recovery method for a device or media failure in a conventional file device.

By the way, in the conventional journal collection method, journals are collected by temporarily accumulating journals when data files are updated in a journal buffer on a volatile memory, converting them into blocks, and outputting the block to a journal file.

[Problem that the invention seeks to solve]

In the conventional journal collection method described above, journals are collected into the journal buffer on volatile memory when a data file is updated, so when a power outage (power outage) occurs, the journal buffer that was being collected is The journal is missing (because the journal up to the final checkpoint is deleted, file recovery using the series of journal files collected up to the time of power off is not possible, and all data files are deleted immediately after power off). The drawback is that the series of journal files that have been collected up to that point must be discarded.

In view of the above-mentioned points, an object of the present invention is to provide a journal collection method that can prevent journal records from being lost (disappeared) up to the final checkpoint when an IS failure occurs.

[Means for solving problems]

The journal collection method of the present invention includes a process group that updates a data file on a file device through an input/output processing means of a file access control section, and a journal collection processing means of the file access control section when updating the data file. In a journal collection method that includes a journal buffer in which journals are collected and a journal output processing process that periodically outputs journal records on this journal buffer to a journal file via a journal output processing means, a nonvolatile high-speed file device is used. and a journal flush processing means that is provided in the journal output processing process and outputs journal records on the journal buffer to the flash file at high speed at each checkpoint of update processing of the data file. [Operation] In the journal collection method of the present invention, a Franche file using a non-volatile high-speed file device is provided,
A journal flush processing means provided in the journal output processing process outputs journal records on the journal buffer to a flash file at high speed at each checkpoint of data file update processing.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

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

The journal collection method of this embodiment uses a plurality of processes 11
~1m (m is a positive integer) data file update process group 1, a file access control unit 2 including an input/output processing means 21 and a journal collection processing means 22, and a data file 31 consisting of, for example, a magnetic disk device. A file device 3, a journal buffer group 4 consisting of a plurality of journal buffers 41 to 4n (n is a positive integer) formed of volatile memory, and a journal output processing means 5
1 and journal flush processing means 52; a journal file 6 comprising, for example, a magnetic tape device; and a journal buffer high-speed evacuation file (hereinafter referred to as a flash) comprising, for example, a high-speed semiconductor disk device with an auxiliary power supply. 71 (referred to as a file).

Referring to FIG. 2, the processes in the journal collection processing means 22 include a journal record acquisition step 221, a journal buffer full determination step 222, a journal buffer switching request step 223, a journal buffer switching end determination step 224, and a journal buffer full determination step 222. From step 225 of waiting for end of switching processing, step 226 of transferring journal records to journal buffer, step 227 of checkpoint determination, step 228 of requesting flush of journal buffer, step 229 of determining end of flush, and step 230 of waiting for end of flush processing. Become.

Referring to FIG. 3, the processes in the journal output processing means 51 include a journal buffer switching request determination step 511, a flush request step 512, a journal buffer switching processing step 513, a journal buffer switching completion notification step 514, and a journal buffer switching completion notification step 514. It consists of a step 515 of outputting an image to a journal file, a step 516 of outputting a journal buffer image to a flash file, a step 517 of notifying completion of flash processing, and a step 518 of waiting processing.

Referring to FIG. 4, the initialization process of the journal output processing process 5 after the power is turned off includes a flash file input step 501, a journal file final block input step 502, and an image match determination step 50.
3, and a step 504 of outputting the flash file image to a journal file.

Note that in this embodiment, each journal buffer 41 to 4n
The storage capacity of one block of the journal file 6 and the storage capacity of the flash file 71 are assumed to be equal. Furthermore, it is assumed that one block consists of a plurality of journal records.

Next, the operation of the journal collection system of this embodiment configured as described above will be explained.

A data file update process group 1 consisting of a plurality of processes 11 to 1+w accesses the data file 31 on the file device 3 via the input/output processing means 21 of the file access control section 2.

Data by data file update process group 1.

When updating the file 31, the file access control unit 2
The journal collection processing means 22 of the input/output processing means 21
Prior to the updating process of the data file 31, the update image of the data file 31 is transferred as a journal record to one of the journal buffers 41 to 4n and converted into a block. Specifically, the journal collection processing means 22 obtains journal records from the input/output processing means 21 (step 221), and determines whether the journal buffer currently collecting journal records (hereinafter referred to as the current journal buffer) is full. By determining whether the obtained journal record can be transferred to the current journal buffer (step 2
22), if the journal record can be transferred to the current journal buffer, the journal collection processing means 22 transfers the journal record to the current journal buffer and blocks it (step 226).
.

If the current journal buffer is full and the obtained journal record cannot be transferred, the journal collection processing means 22 issues a journal buffer switching request to the journal output processing means 51 of the journal output processing process 5 (step 223), The end of the journal buffer switching process is awaited (steps 224 and 225).

The journal output processing means 51 of the journal output processing process 5 constantly monitors the journal buffer switching request from the journal collection processing means 22 (step 511), and when there is a journal buffer switching request from the journal collection processing means 22. (Step 513) Next, the journal output processing means 51 instructs the journal collection processing means 22 to change the journal buffer (for example, from the journal buffer 41 to the journal buffer 42). After notifying the end of the switching process (step 5)
14) Output the image of the blocked journal record on the current journal buffer before switching the journal buffer to the journal file 6 (step 515), and return to step 511.

When the journal collection processing means 22 receives the notification of completion of the journal buffer switching process from the journal output processing means 51 (step 224), it performs a process of transferring journal records to the new switched current journal buffer (step 224). 226).

After transferring the journal record to the current journal buffer, the journal collection processing unit 22 moves to a checkpoint, which is the logical completion point of the update process of the data file 31 (for example, the completion of the update process of the data file 31 by one process). Step 227), and if it is not a checkpoint, the above-mentioned process is repeated.

Further, when the checkpoint is determined in step 227, the journal collection processing means 22 issues a request to flush the journal record on the current journal buffer to the journal output processing means 51 of the journal output processing process 5 (step 228). Wait for the completion of the flush process (steps 229 and 230)
).

The journal output processing means 51 constantly monitors the flush request from the journal collection processing means 22 (step 512), and when there is a flush request from the journal collection processing means 22, it blocks the current journal buffer. The journal flush processing means 52 writes the image of the journal record to the franchise file 71 on the nonvolatile high-speed file device 7 at high speed (step 516), and after the writing process is completed, the journal collection processing means 22 causes the journal collection processing means 22 to finish the flush processing. Step 517 ), Step 51
Return to 1.

If there is no journal buffer switching request or flush request from the journal collection processing means 22, the journal output processing means 51 performs a waiting process (step 518), and then returns to step 511.

As described above, the journal records are sequentially formed into blocks on the journal buffers 41 to 4n, and written into the journal file 6 block by block by the journal output processing means 51.

When a power outage (power outage) occurs, the journal records in the journal buffers 41 to 4n, which are volatile memories, are volatilized and lost. However, since the flash file 71 is secured on the nonvolatile high-speed file device 7, even if a power outage occurs, the journal image of the current journal buffer flashed up to the last checkpoint immediately before the power outage will not disappear. It remains in flash file 71.

In the initialization process of the journal output processing process 5 after a power outage (power outage) occurs, the journal output processing means 51
continues the journal image from the flash file 71 on the nonvolatile high-speed file device 7 via the journal flush processing means 52 (step 50).
1) Read the last block of journal file 6 (step 502) and compare the read journal image and block information (step 503')
, if the two do not match, flash file 71
write the journal image next to the last block of journal file 6 (step 504), rescue the journal records on the current journal buffer up to the last checkpoint when the system is interrupted due to power outage, and then move on to the next process. . If the two match, the process immediately moves to the next step.

In this way, in this embodiment, the data file 31 is updated by writing the journal image stored in the current journal buffer to the flash file 71 at each checkpoint in the update process of the data file 31.
journal records up to the final checkpoint of update processing can be guaranteed.

〔Effect of the invention〕

As explained above, the present invention provides a flash file on a nonvolatile high-speed file device for a journal buffer on a volatile memory, and writes a journal image on a current journal buffer to a flash file at high speed at each checkpoint. This has the effect of preventing journal records from being lost (disappeared) up to the final checkpoint in the event of a power outage.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a journal collection method according to an embodiment of the present invention, FIG. 2 is a flowchart showing the processing of the journal collection processing means in FIG. 1, and FIG. 3 is a journal diagram in FIG. 1. Flowchart showing the processing of the output processing means. FIG. 4 is a flowchart showing the initialization processing of the journal output processing process in FIG. 1 after the power is turned off. In the figure, 1... Data file update process group, 2... File access control unit, 3... File device, 4... Journal buffer, 5... Journal output processing process, 6... Journal File, 7... Nonvolatile high-speed file device, 11-111 Process, 21... Input/output processing means, 22... Journal collection processing means, 31... Data file, 41-4n Journal buffer, 51... Journal output processing means, 52... Journal flush processing means, 71...
It is a flash file. Dimension O Figure 4

Claims (1)

[Claims] A process group for updating a data file on a file device via an input/output processing means of a file access control unit;
a journal buffer from which journals are collected by the journal collection processing means of the file access control unit when the data file is updated; and a journal from which journal records on the journal buffer are periodically output to a journal file via the journal output processing means. A journal collection method having an output processing process, a flash file using a non-volatile high-speed file device, and a journal record on the journal buffer provided in the journal output processing process at each checkpoint of update processing of the data file. A journal collection method, comprising: a journal flush processing means for outputting the information to the flash file at high speed.