Database load distribution processing method and recording medium storing a database load distribution processing program

• US 6,816,860 B2
• Filed: 01/05/2000
• Issued: 11/09/2004
• Est. Priority Date: 01/05/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Hiroshi
• Primary Examiner(s): Corrielus, Jean M.
• Assistant Examiner(s): TRUONG, CAM Y T
• Application Number:
  US09/478,202
• Publication Number:
  US 20030097370A1
• Time in Patent Office: 1,770 Days
• Field of Search: 707/203, 707/200, 707/205, 707/10, 707/204, 709/200, 709/201, 709/204, 709/203
• US Class Current: 707/703
• CPC Class Codes: G06F 16/2471 Distributed queries
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: Y10S 707/922 Communications
• CPC Class Codes: Y10S 707/966 Distributed
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

The abstract of the disclosure “the object of the present invention is to provide a technology that can prevent the reduction of transaction throughput caused by the concentration of load on specific communication resources and server resources. In order to achieve this object, the present invention provides a database load distribution processing method that distributes access to a distributed database managed by a plurality of servers. The method includes: a step for monitoring the activity status of communication resources and managing communication status; a step for monitoring server activity status and managing server status; and a step for distributing access to the distributed database based on information indicating communication status and server status” is required and must be presented on a separate sheet, apart from any other text.

Claims

1. In a database load distribution processing method of distributing access to a distributed database managed by a plurality of servers from a client computer, a database load distribution processing method comprising the steps of:

periodically monitoring activity status of communication resources and managing communication status by said client computer, independent of an access request;

reading the communication status and comparing a preceding communication status with a current communication status by said client computer, before receiving an access request;

periodically monitoring activity status of server and managing server status by said client computer, independent of an access request; and

previously determining, by said client computers, at least one path to be used to access to said distributed database to perform a transaction processing based on said activity status of said communication resources, said activity status of said server and a result of the comparison of the preceding and current communication statuses, independent of arid before receiving an access request, wherein in said step of determining at least one path, selection of priorities for the at least one path are set up at a timing that is not synchronized with requests for access.

2. In a database load distribution processing method of distributing access to a distributed database managed by a plurality of servers from a client computer, a database load distribution processing method comprising the steps of:

periodically monitoring failures, load, and activity status for communication resources and managing communication status by said client computer, independent of an access request;

reading the communication status and comparing a preceding communication status with a current communication status by said client computer, before receiving an access request;

periodically monitoring failures, load, and activity status for servers and managing server status by said client computer, independent of an access request; and

determining, by said client computer, at least one path to be used to access to said distributed database to perform a transaction processing based on failures, load and activity status for said communication resources, failures, load and activity status for said servers and a result of the comparison of the preceding and current communication statuses, independent of and before receiving an access request, wherein in said step of determining at least one path, selection of priorities for the at least one path are set up at a timing that is not synchronized with requests for access.

3. A database load distribution processing method as described in claim 2, further comprising the steps of:

determining a failed path if a failure takes place, setting up a path having a highest selection priority as an alternate path, and retrying a transaction processing generating an error due to said failure using said alternate path.

4. A database load distribution processing method as described in claim 2, further comprising the steps of:

changing the number of paths being used for transaction processing to a number appropriate for a volume of transactions being processed; and

recording transaction processing times indicating processing times required for processing transactions on each of said paths,

wherein in said step for determining at least one path, selection of priorities for the at least one path are set up based on said activity status for communication resources, said activity status for servers status, and transaction processing times.

5. A database load distribution processing method as described in claim 4, wherein in said step of changing said path number, said path number is changed based on a comparison of past transaction processing results and current transact ion volumes.

6. In a database load distribution processing for distributing access to a distributed database managed by a plurality of servers from a client computer, a database load distribution processing device comprising:

means for periodically monitoring activity status of communication resources and managing communication status by said client computer, independent of an access request;

means for reading the communication status and comparing a preceding communication status with a current communication status by said client computer, before receiving an access request;

means for periodically monitoring activity status of server and managing server status by said client computer, independent of an access request; and

means for determining, by said client computers, at least one path to be used to access to said distributed database to perform a transaction processing based on said activity status of communication resources, said activity status of server and a result of the comparison of the preceding and current communication statuses, independent of and before receiving an access request, wherein in said step of determining at least one path, selection of priorities for the at least one oath are set up at a timing that is not synchronized with requests for access.

7. In a database load distribution processing for distributing access to a distributed database managed by a plurality of servers from a client computer, a database load distribution processing device comprising:

a communication status management process module periodically monitoring failure, load, and activity status of communication resources and managing communication status by said client computer, independent of an access request;

a reading and comparison module reading the communication status and comparing a preceding communication status with a current communication status by said client computer, before receiving an access request;

a server status management process module periodically monitoring failure, load, and activity status of servers and managing server status by said client computer, independent of an access request; and

a distributing function path selection management process module determining, by said client computers, at least one path to be used to access to said distributed database to perform a transaction processing based on failures, load and activity status for said communication resources, failures, load and activity status for said servers and a result of the comparison of the preceding and current communication statuses, independent of and before receiving an access request, wherein said distributing function path selection management process module sets up selection priorities of the at least one oath at a timing that is not synchronized with requests for access.

8. In a database load distribution processing device as described in claim 7, the database load distribution processing device further comprising:

an alternate path management process module determining a failed path if a failure takes place, setting up a path having the highest selection priority as an alternate path, and using said alternate path to perform a retry of a transaction processing that generated an error due to said failure.

9. In a database load distribution processing device as described in claim 8, a database load distribution processing device further comprising:

a path selection learning process module changing a number of paths being processed to a path number appropriate for a transaction volume, and recording transaction processing times for each path indicating processing times required by transaction processes,

wherein said distributing function path selection management process module sets up selection priorities of the at least one path based on said communication status and said server status as well as information indicating said transaction processing time, and

wherein said paths are indicated to said client computer based on said selection priority setting.

10. In a database load distribution processing device as described in claim 9, a database load distribution processing device wherein said path selection learning process module changes said path number based on a comparison of past transaction processing results and current transaction volume.

11. A recording medium holding a database load distribution processing program for distributing access load for a distributed database managed by a plurality of servers from a client computer, said database load distribution processing program when executed causes a computer to perform the steps of:

periodically monitoring communication resource failure, load, and activity status, and managing communication status by said client computer, independent of an access request;

reading the communication status and comparing a preceding communication status with a current communication status by said client computer, before receiving an access request;

periodically monitoring server failure, load, and activity status, and managing server status by said client computer, independent of an access request; and

determining, by said client computer, at least one path to be used to access to said distributed database to perform transaction processing based on failures, load and activity status for said communication resources, failures, loads and activity status for said servers and a result of the comparison of the preceding and current communication statuses, independent of and before receiving an access request, wherein in said step of determining at least one path, selection of priorities for the at least one path are set up at a timing that is not synchronized with requests for access.

12. A recording medium holding a database load distribution processing program as described in claim 11, wherein said database load distribution processing program when executed further causes the computer to perform the steps of:

determining a failed path if a failure takes place;

setting up a path having a highest selection priority as an alternate path; and

using said alternate path to retry a transaction processing for which an error was generated due to said failure.

13. In a recording medium holding a database load distribution processing program as described in claim 11, a recording medium holding a database load distribution processing program wherein said database load distribution processing program when executed further causes the computer to perform the steps of:

changing the number of paths being used for processing to a path number appropriate for a volume of transactions being processed; and

recording transaction processing times for each of said paths, said processing times indicating processing times required for processing transactions,

wherein said step of determining at least one path sets up selection priorities for said paths based on said activity status of communication resources, said activity status of servers, and information indicating transaction processing times.