JP2000010853A - Shared area managing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shared area managing method which can improve the system performance even under LRU(least recently used) control. SOLUTION: When information 13 in a shared area 12 is referred to, the said information 13 is read in an information area 10 of a host 1; only when information needs to be registered and updated in the shared area 12, the information 13 in the shared area 12 is read in the information area 10, deletion time information 14 of the shared area 12 is read in a deletion time information area 11 and while the registration and update of the read-in information area 10 are performed, the deletion time information area 11 for deletion candidate selection time is updated. Consequently, the updating process (rewriting process for update information) of the deletion time information 14 which were done each time the information 13 in the shared area 12 is refereed to under the conventional LRU control can be omitted, so that the system performance can be improved even under the LRU control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shared area management method suitable for use in a computer system constituting a cluster system.

[0002]

2. Description of the Related Art Conventionally, as a function of managing a shared area that can be accessed at high speed between hosts of a computer system constituting a cluster system, information for which access such as registration, update, and reference has not occurred for the longest time has occurred. (Least Recently Used) control for selecting a file as a deletion candidate is known.

[0003]

By the way, such L
In the shared area management method based on RU control, after performing a reading process for referring to information stored in the shared area,
It is necessary to write control information (used in LRU control) necessary for selecting information to be changed and deleted due to the reference to the shared area again. For this reason, if the information stored in the shared area is frequently referred to, a large number of such writing processes occur, so that it takes a long time to access the shared area, and the system performance is degraded. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shared area management method capable of improving system performance even under LRU control.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, a shared area in which storage information and information at the time of deletion are stored is stored in an LRU (Least Recently) area.
sed) This is a method of managing by control, and when referring to a shared area, it is necessary to read storage information stored in the shared area into the host side information area, and to register / update the information in the shared area. Only when there is, the storage information stored in the shared area is read into the host-side information area, and the deletion information stored in the shared area is read into the host-side deletion information area. In addition to registration / update, the host-side deletion information area is updated.

In the present invention, when the storage information in the shared area is referred to, the LRU control is performed so that the storage information is only read into the host side information area. The update process of the deletion information can be omitted, and as a result, the access time to the shared area can be shortened and the system performance can be improved.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a computer system according to an embodiment of the present invention. The system shown in FIG. 1 includes a host computer 1 (hereinafter abbreviated as a host) 1 and a shared area 12 which is shared and accessed by the host 1 together with another host (not shown). / Update device 3,
It has a reference device 8, an information area 10, and a deletion information area 11. On the other hand, the shared area 12 includes information 13 and information 14 at the time of deletion.

The registration / update device 3 includes a shared area reading means 4, an information updating means 5, and a shared information writing means 6. The shared area reading means 4 reads the information 13 and the deletion information 14 from the shared area 12 into the information area 10 and the deletion information area 11 of the host 1. The information updating means 5 registers / deletes information 13 from the shared area 12 read into the information area 10 and deletes information 1 from the shared area 12 read into the deleted information area 11.
4, a deletion information area 1 for selecting a deletion candidate
Update 1 The shared information writing means 6 writes the information area 10 of the host 1 into the information 13 of the shared area 12 and the information area at the time of deletion 11 into the information 14 at the time of deletion of the shared area 12. The reference device 8 includes information reading means 9.
The information reading means 9 reads information from the information 13 in the shared area 12 to the information area 10 in the host 1.

In such a system, when a registration / update request 2 for the shared area 12 occurs on the host 1 side, control is passed to the registration / update device 3. Then, the registration / update device 3 first sets the information 1 of the shared area 12
The shared area reading means 4 is started to store the information 3 and the deletion time information 14 in its own information area 10. When the shared area reading unit 4 is activated, the information 13 of the shared area 12 is read.
And the deletion time information 14 are read into the information area 10 and the deletion time information area 11 of the host 1, respectively.

When the information 13 of the shared area 12 is read into the information area 10 and the deletion information 14 of the shared area 12 is read into the deletion information area 11 by the shared area reading means 4, the read information area 10 is read. Information area 11 for registration / update or deletion candidate selection
Is updated, the information updating means 5 is activated. The information updating means 5 registers / updates the information area 10 and, after updating the information area 11 at the time of deletion, passes control to the shared information writing means 6.

Next, the shared information writing means 6 writes the information area 10 of the host 1 in the information 13 of the shared area 12 and the deletion information area 11 in the deletion information 14 of the shared area 12, respectively, and ends the processing. . Then, when the reference request 7 for the information 13 of the shared area 12 occurs, the control is passed to the reference device 8. In the reference device 8, the shared area 12
The information reading means 9 is started to read out the information 13 of. The information reading means 9 includes information 13 of the shared area 12.
Is read into the information area 10 of the host 1, and the process is terminated.

As described above, according to the present invention, when the information 13 of the shared area 12 is referred to, the information 13 of the shared area 12 is read into the information area 10 of the host 1. Only when it is necessary to register / update the information, the information 13 of the shared area 12 is read into the information area 10 and the deletion information 14 of the shared area 12 is read into the deletion information area 11. Register /
In addition to the update, the deletion information area 11 for selecting the deletion candidate is updated, so that the deletion information 14 which is performed every time the information 13 of the shared area 12 is referred to as in the conventional LRU control is used. The update processing (rewrite processing of update information) can be omitted, and thereby the system performance can be improved even under LRU control.

In the above-described embodiment, the processing under a single host has been described. However, the present invention is not limited to this. Of course, it is effective. That is, when a reference request to the information 13 of the shared area 12 occurs,
Control is passed to the reference device 8, which passes control to the information reading means 9 in order to read the information 13 in the shared area 12. When reading the information 13 from the shared area 12, the information reading unit 9 temporarily occupies the shared area 12 in order to exclusively use the shared area 12 with another host. Then, the information reading means 9 reads information from the information 13 of the shared area 12 into the information area 10 of the host 1, and ends the processing. If the number of times of updating the shared area 12 is reduced, the number and time of exclusive use of the shared area 12 are reduced, and the waiting state due to competition with other hosts can be reduced.

[0013]

According to the present invention, when the storage information in the shared area is referred to, the storage information is read only into the host-side information area, and the LRU control is stopped. The process of updating the information at the time of deletion, which is performed each time, can be omitted, and as a result, the access time to the shared area can be shortened, and the system performance can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a computer system according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host 3 Registration / update device 4 Shared area reading means 5 Information updating means 6 Shared information writing means 8 Reference device 9 Information reading means 10 Information area 11 Deletion information area 12 Shared area 13 Information 14 Deletion information

Claims (1)

[Claims] 1. A method for managing a shared area in which storage information and information at the time of deletion are stored by LRU (Least Recently Used) control, wherein when a shared area is referred to, the storage stored in the shared area is controlled. When information is read into the host-side information area, while only when it is necessary to register / update the information in the shared area, the storage information stored in the shared area is deleted in the host-side information area and stored in the shared area. A shared area management method comprising reading information into a host-side deletion information area, registering / updating the read host-side information area, and updating the host-side deletion information area.