JP5819085B2 - Input/Output Control Unit - Google Patents

Description

The present invention relates to an input/output control device.

One example of a system for performing backups is described in Patent Document 1. In this system, a backup server creates a bootable OS image for the target client and records it on media. The client then installs and boots the bootable OS via the media, connecting the client to the backup server via a network. After that, the hard disk to be backed up and the backup destination are selected and notified to the backup server, and after the backup process is performed, the bootable OS automatically shuts down. It has also been customary to set execution priorities for individual application programs. For example, a high priority is set for service programs running in the foreground, and a low priority is set for backup programs running in the background.

JP2002-358245

In backup processing, a large amount of files and data is recorded in an external storage device, for example, a file device such as a hard disk drive. In this case, a large amount of I/O requests are issued to the OS (operating system), which can overwhelm the OS with the processing and adversely affect the processing of application programs running in the background. In other words, even if a program or task has a low execution priority, issuing a large amount of I/O requests can cause the I/O of other application programs to wait, resulting in slower application programs and poor response, which reduces usability for users. Therefore, the present application aims to provide an input/output control device that has less of an effect on application programs even when backup processing is executed in parallel with the running of the application programs.

The present invention has an I/O request receiving unit that receives an I/O request transmitted from a request source and registers the received I/O request in an I/O list prepared for each request source and for each application program , an I/O priority holding unit that holds a priority for each I/O list, and an I/O queue that stores I/O requests to be sent to an I/O device that is an input/output target, wherein the priority of a backup program which is one of the application programs is set relatively lower than the priorities of other programs of the application program, and as a result of this setting, the processing time of the backup program is set relatively shorter than the processing time of the other programs, and the I/O priority holding unit The above-mentioned problem is solved by providing an I/O issuing unit that reads out the priority of each I/O list selected in a circular manner in a predetermined order from the priority setting unit , and repeats the process for the backup program, which is set relatively short as a result of setting the priority of the backup program, and the process for the other programs, which is set relatively long as a result of setting the priority of the other programs of the application program, to read out I/O requests corresponding to the backup program and the other programs registered in the I/O list and store them in an I/O queue, and a priority setting unit that changes the contents of the I/O priority holding unit in response to a user request.

According to the backup system of the present invention, the priority of the I/O processing of the backup program running in the background is set relatively lower than the priority of the I/O processing of the application program running in the foreground, so the load of the I/O processing related to the backup is suppressed and the adverse effect on the processing of the application program is mitigated. This improves usability for users.

FIG. 2 is a diagram illustrating a configuration of a portion related to I/O processing according to an embodiment. 11 is a flowchart illustrating an operation of an I/O request receiving unit of the embodiment. 11 is a flowchart illustrating an operation of an I/O issuing unit according to the embodiment.

Figure 1 shows the configuration of the portion of the backup system relating to I/O processing in an embodiment of the present invention. Reference numeral 10 denotes an application program, which includes not only a service program with a user interface that runs on the front side, but also a backup program that runs on the back side and backs up various data and files created by the service program. When the application program 10 requires various I/O operations, the I/O request sending unit 11 sends the I/O request to the I/O receiving unit. In addition, multiple application programs 10 can be executed simultaneously in parallel, and the backup program performs backup processing even while the front side application program is in operation.

20 is an I/O reception unit, which includes an I/O request reception unit 21 that receives transmitted I/O requests, an I/O list 22 that registers received I/O requests, an I/O issuing unit 23 that extracts I/O requests registered in the I/O list 22 and issues the I/O requests to an I/O processing unit, and an I/O list priority holding unit 24 that holds priority settings. This I/O list priority holding unit 24 is configured as an I/O list priority management table that manages the priority for each I/O list 22.

An I/O list 22 is prepared for each application program 10, and transmitted I/O requests are stored in the I/O list 22 on a first-in, first-out basis for each application program 10 that transmitted them. A priority is set for each I/O list 22, and the priority is registered in the I/O list priority holding unit 24. In this embodiment, this priority is set according to the amount of time that can be continuously performed to issue the I/O requests registered in the I/O list 22 to the I/O queue 31 (the process of storing the I/O requests in the I/O queue 31). The higher the priority, the more processing time is allocated, and therefore the more I/O requests can be issued. The contents of the I/O list priority holding unit 24 are changed by the priority setting unit 25 upon receiving a request from the application program 10.

30 is an I/O processing unit, which includes an I/O queue 31 that stores I/O requests in a first-in, first-out manner, and an I/O means 32 that sequentially retrieves I/O requests stored in the I/O queue 31 and issues I/O, i.e., input/output, instructions to the I/O device that is the target of the I/O request. 40 is an I/O device, which specifically corresponds to, for example, a file device constituted by a hard disk device. The I/O reception unit 20, I/O processing unit 30, and I/O device 40 constitute an input/output control device.

The operation of this embodiment will now be described with reference to Figures 2 and 3. Figure 2 is a flowchart showing the operation of the I/O request receiving unit 21, and Figure 3 is a flowchart showing the operation of the I/O issuing unit 23. When an I/O request is sent from the application program 10 that is the request source, the I/O request receiving unit 11 receives it (step S21) and registers it in the I/O list 22 corresponding to the program that sent the request (step S22).

Meanwhile, the I/O issuing unit 23 selects from a plurality of prepared I/O lists 22 in a predetermined order in a circular manner (step S31), reads the I/O requests registered in the selected I/O list 22, and stores the read I/O requests in the I/O queue 31 (step S33). At this time, the I/O issuing unit 23 acquires the priority set in the I/O list 22 by referring to the I/O list priority holding unit 24 (step S32), and repeatedly executes the process of reading the I/O requests from the I/O list 22 and storing them in the I/O queue 31 for a predetermined processing time corresponding to the priority until the I/O list 22 becomes empty. Then, when the processing time has elapsed or the I/O list 22 becomes empty, the process for the I/O list 22 is terminated, the next I/O list 22 is selected as the processing target, and the same process is executed for the selected I/O list 22.

The I/O means 32 of the I/O processing unit 30 retrieves the I/O requests stored in the I/O queue 31 in a first-in, first-out manner, that is, from the oldest to the newest, and repeats the process of instructing the I/O device 40 to perform input/output. In this way, the I/O requests of the application program 10 are stored in the I/O queue 31 and are sent to the I/O device 40 in the order in which they were stored, and the input/output process is executed.

In this embodiment, the backup program, which is one of the application programs 10, is set to a relatively lower priority than the other application programs 19. Every I/O request sent by the backup program is received by the I/O request receiving unit 21 and temporarily registered in the I/O list 22 for the backup program, but this priority comes into effect when the request is subsequently stored in the I/O queue 31.

In other words, a relatively low priority is set for the I/O list 22 for the backup program, and correspondingly, the processing time that the I/O issuing unit 23 can use to store I/O requests for the backup program in the I/O queue 31 is shorter than the time that can be used for other application programs. This reduces the amount of I/O requests for the backup program stored in the I/O queue 31. As a result, the input/output processing of the backup program is less than the input/output processing of service programs that run on the front side, such as business programs that manage the user interface, and this reduces the deterioration of usability due to slower speeds and slower response times for those business programs.

In addition, the priority setting unit 25 changes the contents of the I/O list priority holding unit 24 in response to a request from the user (application program 10), making it possible to operate the system by flexibly setting priorities according to the usage situation and environment.

10 Application program 20 I/O reception unit 22 I/O list 23 I/O issuing unit 24 I/O list priority holding unit 30 I/O processing unit

Claims (1)

an I/O request receiving unit that receives an I/O request transmitted from a request source and registers the received I/O request in an I/O list prepared for each request source and each application program ; an I/O priority holding unit that holds a priority for each I/O list; and an I/O queue that stores I/O requests to be sent to an I/O device that is an input/output target;
having
a priority of a backup program which is one of the application programs is set relatively lower than the priorities of other programs of the application program, and as a result of this setting, a processing time of the backup program is set relatively shorter than the processing times of the other programs;
an I/O issuing unit which reads out the priority of each I/O list which is circularly selected in a predetermined order from the I/O priority holding unit, and executes reading out an I/O request corresponding to the backup program and the other programs registered in the I/O list and storing it in an I/O queue, by repeating the process time of the backup program which is set relatively short as a result of setting the priority of the backup program and the process time of the other programs which is set relatively long as a result of setting the priority of the other programs of the application program;
a priority setting unit that changes the contents of the I/O priority holding unit in response to a user request;
The input/output control device further comprising: