JPH06250902A - File backup method for distributed system - Google Patents

Abstract

(57) [Summary] [Purpose] The frequency of backups is set according to the importance of files to improve the efficiency of backup processing and reduce the load. [Configuration] A client 10, a server 20, and a backup file server 30 are connected via a communication network 40. A file management table 200 is on the memory 21 of the server 20. In the file management table 200, an update counter for recording the number of file updates and a specified number of updates for backup according to the importance of the file are set for each file. Server 20
Temporarily stores the input data from the client 10 in the management table 200 as the latest information, and then the external storage device 5
Store 0. At this time, the update counter is updated, and when the number of updates matches the specified update count, the server 20 sends a backup of the file to the server 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file backup method in a client / server distributed system, and in particular, it operates 24 hours a day, 365 days a year, taking into account the backup time and the processing load at the time of backup. The present invention relates to a file backup method suitable for making a backup according to the importance of a file in a system that must be used.

[0002]

2. Description of the Related Art Conventionally, large-scale online systems and 2
In a system that operates for 4 hours 365 days, the server is made to perform daily work, and the original work is stopped or degenerated at a certain time of the day, and all files have the same frequency. I had a backup.

As disclosed in Japanese Patent Laid-Open No. 3-48948, for example, there is also a method of backing up a file by prioritizing it depending only on whether there is an update access to the file, but even if it is an important file. If, by chance, a period with few update accesses occurs, the priority of the file may be lowered.

[0004]

Among the files to be backed up, there are some files that are not very important, and conversely, there are files that are very important and should be backed up every time they are updated. In the prior art, since files of different importance were backed up at the same frequency, there were problems such as not being able to back up at the time of down, loss of time for backing up, and reduction of CPU power due to load of backup processing. .
In addition, the method of prioritizing backups according to the presence or absence of update access to files has a problem that even important files cannot be backed up if the access is low.

An object of the present invention is to set a backup frequency according to the importance of a file, thereby improving the efficiency of backup processing and reducing the load of backup processing.

[0006]

In order to achieve the above object, the invention according to claim 1 is a counter for recording the number of file updates in a file management table of a server, and a certain number of updates according to the importance of the file. The specified number of updates to be backed up is set for each file, and when the number of updates and the specified number of updates meet certain conditions, the server itself backs up the file to the backup file server. .

According to the second aspect of the invention, the prescribed number of updates and the prescribed final number of updates are set on the file management table, and even if the prescribed number of updates and the prescribed number of updates satisfy the condition,
If the server itself has a high usage rate and the backup process slows down if you take a backup, continue the update process,
This means that a backup is taken when the number of updates and the specified number of final updates are satisfied.

Further, in the invention of claim 3, the backup file server automatically checks the update counter and the specified update count of the file management table of the server at a certain cycle, This means that the backup file server backs up the file in the server when a certain condition is satisfied.

[0009]

The server updates the data input from the client, once writes it as the latest file information in the file management table, and then stores it in an external storage device or the like. At this time, the update counter is also updated (for example, "1").
Just added). In the file management table, the specified number of updates is set in advance according to the importance of each file, compared with the number of updates, and if a certain condition is satisfied (for example, if it is equal), the server itself or the backup file The server backs up the file.

Also, when the specified number of updates and the update counter satisfy certain conditions and a file is backed up,
Depending on the usage rate of the server itself, determine whether to continue the update processing from the client or make a backup. If the usage rate of the server itself is high and the backup processing slows down, update counter and final Wait for backup until the number of updates meets the conditions.

Thus, the frequency of file backup can be automatically changed according to the importance of the file, the efficiency of the file backup process can be improved, and the load of the backup process can be reduced. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the file backup method of the present invention. In the figure, a plurality of clients 10, a server 20 and a file backup server 30 are connected to a communication network 40. Further, an external storage device 50 is connected to the server 20, and an external storage device 60 is connected to the file backup server 30. There is a file management table 200 in the memory 21 of the server 20, and the external storage device 5
0 has a backup queue 500 for each file.

Each client 10 inputs data and requests the server 20 via the communication network 40 to update the file (the update includes addition and deletion). The server 20 updates the file and returns the processing result to the client 10 via the communication network 40.

The data input from the client 10 is temporarily stored in the file management table 200 prepared on the memory 21 of the server 20 as the latest file information, and then transferred to the backup queue 500 of the corresponding file in the external storage device 50. Be done. In the file management table 200 of the memory 21, a prescribed number of file updates for backup is set for each file in order to change the backup frequency according to the file importance. In addition, the file management table 200 is provided with an update counter that counts the number of times the file is updated.
When the number of updates of a certain file becomes equal to the specified number of updates for backup, the server 20 determines that the external storage device 50
The backup queue 500 of the corresponding file is read from the server, sent to the backup file server 30 via the communication network 40, the update counter of the corresponding file in the file management table 200 is returned to "0", and the corresponding file in the external storage device 50 is backed up. Clear the queue. The backup server 30 writes the backup data sent from the server 20 in the external storage device 60. Furthermore, the file management table 200 on the memory 21 of the server 20 is set with a final update prescribed number other than the backup prescribed update number, and the server 20 is used even if the update number equals the backup prescribed update number. If the rate is high, the process is continued, and when the number of updates reaches the specified number of final updates, the file queue is backed up in the backup file server 50.

The external storage device 50 of the server 20 has file information for each file as the backup queue 500 for a certain period of time, that is, the count number of the update counter is from 1 to the maximum specified number of final updates. The backup file server 30 takes all the data in the external storage device 50 of the server 20 in file units as backup data.

FIG. 2 shows an example of the configuration of the file management table 200 on the memory 21 of the server 20, where 201 is the file name, 202 is the latest file information, 203 is the update counter, 204 is the specified number of backup updates, and 205 is the last. This is the specified number of updates. File name 201 is server 20
It corresponds to each file included in. The file latest information 202 shows the latest update file information, and the data input from the client is stored. The update counter 203 indicates the number of times the file has been updated, and is incremented by "1" when the corresponding file is updated. The specified backup update count 204 and the final updated update count 205 are the update counts of the backup start conditions, and are set for each file in advance according to the importance of the file.

When the server 20 updates the file,
Corresponding table name 20 of this file management table 200
First, the count value of the update counter 203 corresponding to 1 is compared with the specified backup update count 204, and if it is equal, a backup is made to the backup file server 30 when the usage rate is low depending on the usage status of the server 20 itself. . When the usage rate of the server 20 itself is high, the backup process is not performed, and then the file update process from the client is performed until the specified final update count 205 and the update counter 203 become equal, and the backup is performed at the time when the equal is obtained. Take Here, for a file having a very high degree of importance, if the final update prescribed number 205 is made equal to the backup update prescribed number 204 and the set number is made small, backup can be performed in a short cycle.

FIG. 3 shows an example of the configuration of the backup queue 500 on the external storage device 50 of the server 20, where 501 is a file name, 502 is a count value, and 503 is a count value 5.
This is file information for 02. The file name 501 corresponds to the file name 201 in FIG. Count value 502
Indicates the value of the update counter 203 in FIG. 2, and the file information 503 indicates the latest file information 202 at that time. The backup queue 500 exists for each file of the server 20, and holds the file information 503 for each count value 502 from 1 to the maximum number of times of the final update. When backing up to the backup file server 30, the queue data for all the counts for each file is taken as backup data from the external storage device 50.

Next, referring to the flowchart of FIG. 4, the processing when the data is input from the client 10, the file of the server 20 is updated, and the server 20 backs up to the backup file server 30 will be described in detail. explain.

The backup specified update count 204 corresponding to the file a (file name 201 is a) in the file management table 200 on the memory 21 of the server 20 is set to y, and the final update update count 205 is set to z (however, In this embodiment, y <z). These setting values are arbitrarily decided by the user according to the importance of the file. For example, it is a very important file, and if you want to make a backup each time it is updated, the specified backup update count 20
4 is set to "1", and the specified number of final updates 205 is also set to "1".

It is assumed that the client 10 inputs the data and updates the data of the file a of the server 20 (step 401). The server 20 once writes the data input from the client 10 to the file latest information 202 of the file name a in the file management table 200 on the memory 20, and the update counter 203 adds "1" (step 402) (this Let x be the number of hours counter). In the case of deletion, the deleted file data may be written in the file latest information 202 of the corresponding file name in the file management table 200. Update counter 2 for file name a in this file management table 200
03 update count number x and the latest file information 202 are stored in the backup queue 5 of the file name a of the external storage device 50.
It is stored at the end of 00 (step 403).

Next, the server 20 determines the value x of the update counter 203 of the file name a in the file management table 200.
And the value y of the specified backup update count 204 are compared (step 404). When x <y, the server 2
0 continues the data update process from the client 10 without taking a backup of the file a. In this way, the update count numbers x + 1, x + 2, ... And the latest file information corresponding thereto are written in the backup queue 500 of the file name a of the external storage device 50 until x = y.

When x = y, it is determined whether the utilization rate of the server 20 is low (step 405). When the utilization rate is low, the server 20 updates the backup queue 500 of the file name a from the external storage device 50. Number 1 to x (x =
The file data up to y) is read and sent to the backup transmission queue (step 406), and the backup file server 30 is notified of the backup (step 407).

When x = y and the usage rate of the server 20 is high, the value x of the update counter 203 is compared with the value z of the prescribed number of final updates 205 (step 408). If x <z, the server 20 is compared. Continues the data update process from the client 10 without taking a backup of the file a. In this embodiment, y <z, and therefore x = y, x
<Z, and the data update process from the client 10 is continued.

After that, the server 20 executes the data update process n
Continuing, the step x404 determines x> y (however,
x <z), and when it is determined in step 405 that the utilization rate of the server 20 is low, the server 20 counts 1 to x (x = y + n) of the backup queue 500 of the file name a from the external storage device 50. The file data up to () are backed up in the backup file server 30 (steps 406 and 407). On the other hand, if the usage rate of the server 20 is still high, x> z in step 408.
Is determined, the server 20 continues the data update process from the client. In this way, the server 20 continues the data update process n times more, and x = z in step 408.
If it is determined, the server 20 backs up the file data of the update count number 1 to x (x = z) of the backup queue 500 of the file name a from the external storage device 50 regardless of the usage rate. Thirty
Backup as a backup (steps 406, 40)
7).

Here, the utilization rate (busy rate) of the server 20
An example of the measuring method will be described. The first method is to use a hardware monitor, which uses a processor (CP
U) is working or not, hardware monitor samples by very short cycle and checks,
For example, if the sample is sampled 100 times and it makes 70 turns, the utilization rate is 70%. The second method is not as accurate as the hardware monitor, but the sampling is not the hardware but the software monitor is a core part of the operating system (OS) (kernel, which is always used in actual arithmetic processing). This is a method of sampling whether or not a part of software is running. However, since the software monitor itself is software, an overhead is generated when the software monitor operates, and thus the accuracy is lower than that of the hardware monitor. In this embodiment, the utilization rate measured by this hardware monitor or software monitor is 70%, for example.
If it is below, the utilization rate is low, and if it is 70% or more, the utilization rate is high.

Next, when a failure occurs in the server 20 and the update count number does not reach the specified update count for backup and the file information is lost, that is, the file information is lost before the backup is performed in the backup file server 30. The recovery method in case of doing is explained.

When the server 20 is down and the latest file information 202 on the file management table 200 in the memory 21 is lost (for example, the update counter 203 is down due to m), it is stored in the external storage device 50 after the server is restored. The file information 503 whose update count number 502 is m is written in the file latest information 202 of the file management table 200. In this case, the update counter 203 continues counting from m.

When the external storage device 50 of the server 20 goes down and the file information up to the update count number 1 to m is lost, after the external storage device 50 is restored, the input data up to the update count number 1 to m of the journal and All the processes are reproduced from the process contents, and the file information of 1 to m is stored in the external storage device 50. In this case, the update counter 203 of the file management table 200 continues counting from m. To this end, the server 20 needs to separately hold the processing content as a so-called journal file for a certain period of time, for example, as input data from the update count number to the final update prescribed number.

When the server 20 goes down and all the information in the file management table 200 and the file information in the external storage device 50 are also lost, after the recovery of the server 20 and the external storage device 50, the journal update count numbers 1 to m All the processes are reproduced from the input data and the process contents, the file information of 1 to m is stored in the external storage device 50, and
The latest file information 20 is added to the file management table 200.
As 2, the file information of the update count number m is written.
In this case, the update counter 203 continues counting from m.

In any case of failure, after the file information is recovered, the backup file server 30 is considered in consideration of safety.
First, the file information from 1 to m is backed up and the update counter 20 of the file management table 200 is taken.
The process may be continued after setting the value of 3 to "0".

The embodiment of the present invention has been described above, but in the server 20, the management table 20 in the memory 21 is described.
0 is set for each file as a backup timer to automatically take a backup at a fixed cycle,
If necessary, when the set values of the timer and the backup timer of the server 20 satisfy certain conditions, the server 2
It is also possible that 0 automatically sends a backup of the file to the backup file server 30. Further, either the time when the count value of the update counter 203 of the management table 200 and the value of the specified number of times of update 204 satisfy the condition, or the time when the set values of the timer and the backup timer of the server 20 meet certain conditions, whichever comes first. The server 20 may automatically send a backup of the file to the backup file server 30 when the condition is satisfied.

Further, in the embodiment, the server 20 itself sends the backup of the file to the backup file server 30, but the backup file server 30 automatically sends the memory 2 of the server 20 at a fixed cycle.
Update counter 20 of the file management table 200 on 1
3 and the update count 204, and the update counter 20
The backup file server 30 may back up the file in the external storage device 50 of the server 20 when the count value of 3 and the specified update count 204 satisfy certain conditions.

[0035]

According to the first aspect of the present invention, the backup frequency for each file can be controlled by the number of update accesses to the file according to the importance of the file. For files with a small number of backups, the number of backups can be reduced, and the backup processing time can be shortened.

According to the second aspect of the present invention, the backup timing can be controlled depending on the utilization rate of the server, so that the backup processing load can be reduced.

According to the third aspect of the invention, since the backup file server is allowed to perform the backup operation, the load on the server can be further reduced.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a configuration example of a file management table of a server.

FIG. 3 is a diagram showing a configuration example of a backup queue in an external storage device of a server.

FIG. 4 is a flowchart illustrating an example of a server backup process.

[Explanation of symbols]

 10 Client 20 Server 30 Backup File Server 40 Communication Network 50 External Storage Device 200 File Management Table 201 File Name 202 File Latest Information 203 Update Counter 204 Update Rule Count 205 Final Update Rule Count 500 Backup Queue 501 File Name 502 Update Count Value 503 File information

Claims (3)

[Claims] 1. A one or a plurality of clients that input and output data to and from a server, and a server that holds a plurality of files, processes the data input from the clients, and stores the file update data in a storage device. A file backup method in a distributed system comprising a backup file server for backing up files of a server, and a communication network connecting the client, the server and the backup file server, wherein the server An update counter that counts the number of updates of the file and a file management table that sets a specified number of updates that defines the number of updates for making a backup, and the count value of the update counter and the value of the specified number of updates are predetermined. When the conditions are met,
A file backup method for a distributed system, wherein data of the file in the storage device is sent as backup data to the backup file server. 2. The file management table sets, for each file, the prescribed update count for backup in addition to the prescribed update count, and the server updates the update count when the utilization rate of the server is low. If the count value of the counter matches the value of the specified number of updates, take a backup,
When the utilization rate of the server is high, even if the count value of the update counter matches the specified update count value, the processing is continued without backing up, and the count value of the update counter is set to the final update specified count value. 2. The file backup method for a distributed system according to claim 1, wherein a backup is taken at the time when the value of is matched. 3. One or a plurality of clients that input and output data to and from a server, and a server that holds a plurality of files, processes the data input from the clients, and stores the file update data in a storage device. A file backup method in a distributed system comprising a backup file server for backing up files of a server, and a communication network connecting the client, the server and the backup file server, wherein the server An update counter that counts the number of updates of the file and a file management table that sets a specified number of updates that defines the number of updates for taking a backup, and the backup file server automatically updates the server at regular intervals. Counter and specified number of updates The distributed system, wherein the backup file server takes the file data in the storage device of the server as backup data when the count value of the update counter and the specified number of updates satisfy certain conditions. File backup method.