Information processing system and recording medium recording a program to cause a computer to execute steps

• US 6,557,088 B2
• Filed: 07/17/2002
• Issued: 04/29/2003
• Est. Priority Date: 03/30/1999
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Tamura, Takayuki
• Primary Examiner(s): Ellis, Kevin L.
• Application Number:
  US10/196,184
• Publication Number:
  US 20020174294A1
• Time in Patent Office: 286 Days
• Field of Search: 711/151, 711/158
• US Class Current: 711/158
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0674 Disk device

Abstract

An information processing system which has a disk buffer for temporarily storing data items read from a disk unit, a block processing order determination module for detecting, from a processing request for requesting data items stored on the disk unit, a data item matching the data stored in the disk buffer from the data items requested in the processing request and determining the read order of the data item matching and the remaining data requested in the processing request so that the data item matching is read before the remaining data, and a read module for reading the data item matching from the disk buffer before reading the remaining data into the disk buffer from the disk unit in accordance with the read order determined by the block processing order determination module.

Claims

1. An information processing system comprising:

priority determination means for accepting a first processing request for requesting data and a second processing request for requesting a smaller quantity of data than in the first processing request and assigning a priority to the second processing request higher than the priority of the first processing request involving a larger data quantity based on the data quantities requested in the first and second processing requests; and

read means for reading the data in the processing request assigned the higher priority from a storage unit, in precedence over data in any other processing request.

2. The information processing system as claimed in claim 1, wherein said priority determination means determines the priority of the first processing request based on a threshold data quantity and the data quantity involved in the first processing request and the priority of the second processing request based on the threshold data quantity and the data quantity involved in the second processing request.

3. The information processing system as claimed in claim 1, wherein

if said priority determination means accepts the second processing request later while said read means is reading the first processing request, said priority determination means again determines the priorities, and

said read means interrupts reading of the data requested in the first processing request and reads the data requested in the second processing request based on the priorities again determined by said priority determination means, and restarts reading of the data requested in the first processing request after completion of reading the data requested in the second processing request.

4. The information processing system as claimed in claim 1, wherein

the first and second processing requests are requests for accessing different files, and

said read means reads a file related to the first processing request and a file related to the second processing request based on the priorities of the first and second processing requests.

5. A recording medium recording a program for causing a computer to execute:

a first acceptance step accepting a first processing request for requesting data;

a first read step reading data related to the first processing request into buffer storage means from a disk unit;

a second acceptance step accepting a second processing request for requesting data during execution of said first read step;

a comparison step executed after said second acceptance step, comparing a first data quantity involved in the first processing request with a second data quantity involved in the second processing request;

a second read step interrupting said first read step, reading data related to the second processing request from the disk unit, and transmitting the read data to a requesting party making the second processing request if the second data quantity is smaller than the first data quantity; and

a third read step executed after termination of said second read step, restarting execution of said first read step that was interrupted.

6. The recording medium as claimed in claim 5, wherein

the second processing request is a processing request for accessing a plurality of files,

said comparison step includes sorting a file related to the first processing request and files related to the second processing request according to an access order in ascending order of sizes of the files,

said second read step includes reading the files related to the second processing request into the buffer storage means from the disk unit in the access order and transmitting data in the files read to the requesting party, and

even if said second read step is not yet complete, if said second read step accesses a file common to the first processing request, said third read step reads data in the file common to the first processing request from the buffer storage means.

7. The recording medium as claimed in claim 6, wherein at said second read step, an unprocessed block of a plurality of blocks in the file common to the first processing request is read, taking precedence over other blocks, into the buffer storage means from the disk unit by a task for processing the first processing request and then a block unprocessed for the second processing request is read into the buffer storage means from the disk unit.