Redundancy system having synchronization function and synchronization method for redundancy system

• US 7,475,284 B2
• Filed: 03/17/2006
• Issued: 01/06/2009
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Koike, Tomotake
• Primary Examiner(s): Iqbal; Nadeem
• Application Number:
  US11/377,187
• Publication Number:
  US 20060224918A1
• Time in Patent Office: 1,026 Days
• Field of Search: 714/2, 714 3- 13, 714/15, 714/18, 714/26, 714/37, 714/39
• US Class Current: 714/12
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups

Abstract

A redundancy system that can perform synchronization even if a failure occurs to an application. According to the redundancy system of the present invention, a synchronization data memory area, a management bit map table having a flag created for each segment of the synchronization data memory area, and a management memory area for storing the starting address of the segment are set in each device. In the service application process, a service is performed using one or more segments, a flag corresponding to the segment is set, and synchronization information is written to the management memory each time the segment is written or overwritten. In the read process, each flag in the management bit map table is checked, and if a flag being set exists, the synchronization data is read from the segment corresponding to the synchronization information stored in the management memory, and the flag is reset.

Claims

1. A redundancy system, comprising:

a plurality of devices of which the active status and standby status can be switched;

a synchronization data memory installed in each of said plurality of devices;

a management bit map table having a flag created for each segment of said synchronization data memory in an active device;

a management memory for storing synchronization information including a starting address of said segment;

a first processor for performing service using one or a plurality of said segments, and setting said flag corresponding to said segment and writing said synchronization information to said management memory each time said segment is written or overwritten; and

a second processor for checking each flag in said management bit map table at a predetermined timing, and reading synchronization data from said segment corresponding to said synchronization information stored in said management memory and resetting said flag if a flag being set exists.

2. The redundancy system according to claim 1, wherein said active device further comprises a third processor for receiving said synchronization information and said synchronization data from said second processor, and creating a synchronization data management table including said synchronization information and said synchronization data.

3. The redundancy system according to claim 2, wherein said third processor sends information included in said synchronization data management table to another device.

4. The redundancy system according to claim 3, wherein said active device further comprises a system manager for monitoring the operation of said first processor and deciding the transmission timing of said third processor based on the monitoring result.

5. The redundancy system according to claim 4, wherein said active device further comprises a data duplication controller for sending a transmission start instruction and communication control information, for sending information included in said synchronization data management table to another device, to said third processor when said instruction is received from said system manager.

6. The redundancy system according to claim 5, wherein said standby device further comprises a fourth processor for creating said synchronization data management table using information received from said third processor.

7. The redundancy system according to claim 6, further comprising a fifth processor for synchronizing stored data of said synchronization data memories in said active device and said standby device by overwriting the stored data of said synchronization data memory in said standby device using said synchronization data management table created by said fourth processor.

8. The redundancy system according to claim 6, wherein said fourth processor synchronizes the stored data of said synchronization data memories in said active device and said standby device by overwriting the stored data of said synchronization data memory in said standby device using said synchronization data management table created by said fourth processor.

9. The redundancy system according to claim 1, wherein the stored data of said synchronization data memory includes an instance constructed by an object oriented program.

10. The redundancy system according to claim 1, wherein said synchronization data memory and said management bit map table are installed for each said first processor.

11. The redundancy system according to claim 1, wherein said management memory for storing synchronization information further includes information which indicates a size of said segment.

12. A synchronization method for a redundancy system, comprising:

a first step of setting a synchronization data memory area in each shared memory of a plurality of devices of which active status and standby status can be switched;

a second step of setting a management bit map table having a flag created for each segment of a synchronization data memory area in said shared memory in an active device;

a third step of setting a management memory area for storing synchronization information including a starting address of said segment in said shared memory of the active device;

a fourth step of causing a processor to execute a service application process of performing service using one or a plurality of said segments, and setting said flag corresponding to said segment and writing said synchronization information to said management memory area each time said segment is written or overwritten; and

a fifth step of causing said processor to execute a read process of checking each flag in said management bit map table at a predetermined timing, and reading synchronization data from said segment corresponding to said synchronization information stored in said management memory area and resetting said flag when a flag being set exists.

13. The synchronization method according to claim 12, further comprising a sixth step of causing a data duplication library to receive said synchronization information and said synchronization data from said read process, and to create a synchronization data management table including said synchronization information and said synchronization data.

14. The synchronization method according to claim 13, further comprising a seventh step of causing the data duplication library to send information included in said synchronization data management table to another device.

15. The synchronization method according to claim 14, further comprising an eighth step of causing a system manager to monitor the operation of said service processor and to decide the transmission timing of said data duplication library based on the monitoring result.

16. The synchronization method according to claim 15, further comprising a ninth step of a data duplication controller sending a transmission start instruction and communication control information, for sending information included in said synchronization data management table to another device, to said data duplication library when said instruction is received from said system manager.

17. The synchronization method according to claim 16, further comprising a tenth step of the data duplication library of said standby device creating a synchronization data management table using information received from the data duplication library of said active device.

18. The synchronization method according to claim 17, further comprising an eleventh step of synchronizing the stored data of said synchronization data memories in said active device and said standby device by overwriting the stored data of said synchronization data memory in said standby device using said synchronization data management table created by the data duplication library in said standby device.

19. The synchronization method according to claim 17, further comprising an eleventh step of the data duplication library of said standby device synchronizing the stored data of said synchronization data memories in said active device and said standby device by overwriting the stored data of said synchronization data memory in said standby device using said synchronization data management table created by said data duplication library.

20. The synchronization method according to claim 12, wherein said stored data of said synchronization data memory includes an instance constructed by an object oriented program.

21. The synchronization method according to claim 12, wherein said synchronization data memory and said management bit map table are created for each said service application process.

22. The synchronization method according to claim 12, wherein said management memory for storing synchronization information further includes information which indicates a size of said segment.