Minimizing replication search on failover

• US 8,543,545 B2
• Filed: 06/29/2011
• Issued: 09/24/2013
• Est. Priority Date: 06/29/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Holden, Russell, Spencer, William A
• Primary Examiner(s): LE, DEBBIE M
• Application Number:
  US13/172,797
• Publication Number:
  US 20130006933A1
• Time in Patent Office: 818 Days
• Field of Search: 707634-638
• US Class Current: 707/637
• 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: G06F 16/273 Asynchronous replication or reconciliation

Abstract

A method, system, and program product are provided for minimizing replication when a new server is replicated with. A replication application for a client computer having a replica of a database thereon is executed by a processor in a computer to receive for a replication service comprising a plurality of servers containing replicas of the database, an indication of each healthy server in the replication service and a determined period of time within which replication is assured to have been completed for each healthy server. The replication application updates a replication history after successful completion of each replication by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and an imputed timestamp adjusted for the determined period of time.

Claims

1. A computer-based method for minimizing replication when a new server is replicated with, comprising:

a replication application for a client computer having a replica of a database thereon executed by a processor in a computer to receive for a replication service comprising a plurality of servers containing replicas of the database, an indication of each healthy server in the replication service and a determined period of time within which replication is assured to have been completed for each healthy server in the replication service; and

the replication application updating a replication history after successful completion of each replication by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and an imputed timestamp adjusted for the determined period of time.

2. The method of claim 1, wherein each replication history entry has a timestamp for sent to server time and a time stamp for received from server time.

3. The method of claim 1, wherein the imputed time stamp is calculated by subtracting the determined period of time from the time of replication.

4. The method of claim 1, wherein the indication of each healthy server in the replication service and the determined period of time are published by the replication service.

5. The method of claim 1, wherein the indication of each healthy server only indicates servers that have been continuously on line for longer than the determined period of time.

6. The method of claim 1, wherein the replication application is stored on a memory in the client computer and executed by a processor in the client computer.

7. The method of claim 1, wherein the replication application is stored on a memory in at least one of the plurality of servers and executed by a processor in the at least one of the plurality of servers.

8. A computer-based method for minimizing replication when a new server is replicated with, comprising:

a replication service comprising a plurality of servers containing replicas of a database, identifying each healthy server in the service and determining a period of time within which replication is assured to have been completed for each healthy server in the replication service; and

the replication service providing the identification of each healthy server and the determined period of time to a client computer having a replica of the database thereon;

whereby the client computer updates a replication history after successful completion of each replication with a server of the replication service by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and a timestamp adjusted for the determined period of time.

9. A computer system for minimizing replication when a new server is replicated with, comprising:

a replication service comprising at least two servers;

at least one processor in each of the at least two servers;

at least one memory in each of the at least two servers operably connected to the at least one processor in the respective server and having encoded thereon a replica of a database;

a program of instruction encoded on the at least one memory of each of the at least two of servers and executable by the at least one processor of each of at least two servers, the program of instruction comprising;

program instructions to identify each healthy server in the replication service and determine a period of time within which replication is assured to have been completed for each healthy server in the replication service;

program instructions to provide the identification of each healthy server and the determined period of time to a replication application; and

program instructions to update a replication history after successful completion of each replication by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and an imputed timestamp adjusted for the determined period of time.

10. The computer system of claim 9, wherein the program of instruction is stored on a client computer having a replica of the database thereon.

11. The computer system of claim 9, wherein the program of instruction is stored on the at least two server.

12. A computer system comprising at least one client computer, having at least one processor, at least one memory operably connected to the at least one processor, a replication history stored on the at least one memory, and a program of instruction encoded on the at least one memory and executed by the at least one processor to minimize replication when a new server is replicated with, the program of instruction comprising:

program instructions to receive from a replication service comprising a plurality of servers containing replicas of the database, an indication of each healthy server in the replication service and a determined period of time within which replication is assured to have been completed for each healthy server in the replication service;

program instructions to update the replication history after successful completion of each replication by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and an imputed timestamp adjusted for the determined period of time.

13. The computer system of claim 12, wherein each replication history entry has a timestamp for sent to server time and a time stamp for received from server time.

14. The computer system of claim 12, wherein the imputed time stamp is calculated by subtracting the determined period of time from the time of replication.

15. The computer system of claim 12, wherein the indication of each healthy server in the replication service and the determined period of time are published by the replication service.

16. The computer system of claim 12, wherein the indication of each healthy server only indicates servers that have been continuously on line for longer than the determined period of time.

17. A program product for minimizing replication when a new server is replicated with, comprising a non-transitory computer readable storage medium having encoded thereon a computer executable program of instructions, comprising:

program instructions to receive for a replication service comprising a plurality of servers containing replicas of a database, an indication of each healthy server in the replication service and a determined period of time within which replication is assured to have been completed for each healthy server in the replication service; and

program instructions to update a replication history after successful completion of each replication by adding an entry comprising an identification for the server replicated with and a timestamp for the time of replication and by adding an entry for each other healthy server in the replication service containing an identification for the respective server and an imputed timestamp adjusted for the determined period of time.