NO DATA LOSS IT DISASTER RECOVERY OVER EXTENDED DISTANCES

• US 20070079171A1
• Filed: 09/22/2006
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Aidun, Mehrdad
• Granted Patent: US 7,577,868 B2
• Time in Patent Office: Days
• US Class Current: 714/6
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2076 Synchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation

Abstract

Systems and methods operating over extended distances provide for recovery of data and operational continuity of computer applications accessing data within an information technology system if an event occurs effecting access to the data. In one embodiment, an extended distance data recovery system (100) includes first, second and third data storage devices (112, 122, 132) located at respective first, second and third sites (110, 120, 130). The second and third sites (120, 130) are remotely located from the first site (110) with the second site (120) being nearby the first site (110). The first data storage device (112) has data (116) stored thereon. A computer executable control process (150) directs synchronous replication of the data (116), either at the storage level or at the application level, onto the second data storage device (122). The control process (150) also directs asynchronous replication of the data (116) from the second data storage device (122) onto the third data storage device (132) and coordinates among the three sites (110, 120, 130) the state of application servers, storage replication, network address changes, and other prerequisite aspects of the IT infrastructure required to allow the application servers to successfully start at the disaster recovery site.

Claims

1. An extended distance data recovery system comprising:

a first data storage device located at a first site, said first data storage device storing the data thereon;

a second data storage device located at a second site, said second data storage device being communicatively connected with said first data storage device;

a third data storage device located at a third site, said third data storage device being communicatively connected with said second data storage device;

a computer executable control process executable to direct synchronous replication of the data onto said second data storage device;

said control process being further executable to direct asynchronous replication of the data from said second data storage device onto said third data storage device.

2. The system of claim 1 wherein the control process directs synchronous replication of the data onto said second storage device at an application level.

3. The system of claim 1 wherein the control process directs synchronous replication of the data onto said second storage device at a data storage level.

4. The system of claim 1, wherein said control process is further executable to monitor an operational status of said first data storage device and, upon occurrence of an event effecting availability of the data from said first data storage device, update location identifying information associated with the data wherein a computer application accesses the data from one of said second site and said third site.

5. The system of claim 4, wherein said control process updates said location identifying information with one or more domain name servers.

6. The system of claim 1, wherein said third site is geographically separated from said first and second sites, and wherein said second site is geographically separated from said first and third sites.

7. The system of claim 6, wherein a maximum allowable geographical separation distance between said first and second sites varies depending upon application sensitivity to a roundtrip packet delay time between said first and second sites and architectural and operational conditions of a data network connecting said first and second sites.

8. The system of claim 6, wherein said first and second sites are geographically separated such that a maximum roundtrip packet delay time over a data network connecting said first and second sites is in the range of 0.5 milliseconds to 10 milliseconds.

9. The system of claim 1, wherein said control process is executable on a computer system is located at a fourth site.

10. The system of claim 1, wherein said control process is executable on a computer system located at any one or more of said first, second and third sites.

11. The system of claim 1, wherein said control process comprises instances thereof executable on computer systems located at each of said first, second and third sites.

12. The system of claim 1 further comprising:

at least two independent sets of one or more data storage devices located at said first site, said first data storage device being included in one of said sets, wherein a first one of said sets of one or more data storage devices has a first set of data stored thereon, and wherein a second one of said sets of one or more data storage devices has a second set of data stored thereon;

a set of one or more data storage devices located at said third site, said third data storage device being included in said set of data storage devices located at said third site; and

a set of one or more data storage devices located at a fourth site;

wherein said control process is executable to direct synchronous replication of the first and second sets of data from said first and second sets of one or more data storage devices located at said first site onto said second data storage device located at said second site; and

wherein said control process is further executable to direct asynchronous replication of the first set of data from said second data storage device located at said second site onto said set of one or more data storage devices located at said third site and asynchronous replication of the second set of data from said second data storage device located at said second site onto said set of one or more data storage devices located at said fourth site.

13. A method for providing recovery of data and operational continuity of computer applications accessing the data if an event occurs effecting access to the data on an information technology system, said method comprising the steps of:

storing the data at a first site;

synchronously replicating the data from the first site to a second site, wherein synchronous replication of the data is performed under the direction of a computer executable control process;

asynchronously replicating the data from the second site onto a third site, wherein asynchronous replication of the data is performed under the direction of the control process;

monitoring an operational status of the first site; and

updating, upon occurrence of the event, location identifying information associated with the data wherein the computer applications access the data from at least one of the second site and the third site.

14. The method of claim 13 wherein said step of synchronously replicating the data from the first site to the second site is performed at an application level.

15. The method of claim 13 wherein said step of synchronously replicating the data from the first site to the second site is performed at a data storage level.

16. The method of claim 13, wherein said updating comprises updating the location identifying information with one or more domain name servers.

17. The method of claim 13 wherein, in said steps of synchronously replicating and asynchronously replicating, the third site is geographically separated from the first and second sites, and wherein the second site is geographically separated from the first and third sites.

18. The method of claim 17 wherein, in said step of synchronously replicating, a maximum allowable geographical separation distance from the first site and the second site varies depending upon application sensitivity to a roundtrip packet delay time between said first and second sites and architectural and operational conditions of a data network connecting said first and second sites.

19. The method of claim 17 wherein, in said step of synchronously replicating, the first and second sites are geographically separated such that a maximum roundtrip packet delay time over a data network connecting the first and second sites is in the range of 0.5 milliseconds to 10 milliseconds.

20. The method of claim 13 further comprising:

executing the control process on a computer system located at a fourth site.

21. The method of claim 13 further comprising:

executing the control process on a computer system located any one or more of said first, second and third sites

22. The method of claim 13 further comprising:

executing instances of the control process on computer systems located at each of said first, second and third sites.

23. The method of claim 13 further comprising:

storing additional data at the first site;

synchronously replicating the additional data from the first site to the second site, wherein synchronous replication of the additional data is performed under the direction of the computer executable control process; and

asynchronously replicating the additional data from the second site to a fourth site, wherein asynchronous replication of the additional data is performed under the direction of the control process.

24. A system providing for recovery of data and operational continuity of computer applications accessing the data if an event occurs effecting access to the data on an information technology system, said system comprising:

means for storing data at a first site;

means for storing data at a second site;

means for synchronously replicating the data from the first site to the second site;

means for storing data at a third site;

means for asynchronously replicating the data from the second site onto a third site; and

means for monitoring an operational status of the first site and updating, upon occurrence of the event, location identifying information associated with the data wherein the computer applications access the data from at least one of the second site and the third site.

25. The system of claim 24 wherein said means for storing data at a first site comprise a first data storage device, said means for storing data at a second site comprise a second data storage device, and said means for storing data at a third site comprise a third data storage device.

26. The system of claim 24 wherein said means for synchronously replicating the data, said means for asynchronously replicating the data, and said means for monitoring comprise a computer executable control process.

27. The system of claim 24 wherein said means for synchronously replicating the data from the first site to the second site replicate the data at an application level.

28. The system of claim 24 wherein said means for synchronously replicating the data from the first site to the second site replicate the data at a data storage level.

29. The system of claim 24, wherein the third site is geographically separated from the first and second sites, and wherein the second site is geographically separated from the first and third sites.

30. The system of claim 29, wherein a maximum allowable geographical separation distance between the first and third sites varies depending upon application sensitivity to a roundtrip packet delay time between said first and second sites and architectural and operational conditions of a data network connecting said first and second sites.

31. The system of claim 29, wherein said first and second sites are geographically separated such that a maximum roundtrip packet delay time over a data network connecting the first and second sites is in the range of 0.5 milliseconds to 10 milliseconds.

32. The system of claim 24 further comprising:

means for storing additional data at the first site, wherein said means for synchronously replicating are also for synchronously replicating the additional data onto said means for storing data at the second site; and

means for storing data at a fourth site, wherein said means for asynchronously replicating are also for asynchronously replicating the additional data from said means for storing data at the second site to said means for storing data at the fourth site.