System and method for highly reliable data replication

• US 8,554,725 B2
• Filed: 05/22/2012
• Issued: 10/08/2013
• Est. Priority Date: 02/19/2009
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Wang, Haihong
• Primary Examiner(s): GIRMA, ANTENEH B
• Application Number:
  US13/477,999
• Publication Number:
  US 20120239778A1
• Time in Patent Office: 504 Days
• Field of Search: None
• US Class Current: 707/610
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

Data replication includes generating replication data that is part of a replicated file system to be sent over a communication channel to a destination replication device; adding additional verification information to at least a portion of the replication data to prevent data corruption; and sending the replication data and the additional verification information over the communication channel to the destination replication device. The replication data with additional verification information is sent over the communication channel using a reliable protocol that allows the replication data to be verified by the reliable protocol at the destination replication device. The reliable protocol is a protocol capable of detecting most but not all data corruption introduced by the communication channel. The additional verification information includes information for verifying that replication data sent using the reliable protocol does not include data corruption that was introduced by the communication channel and undetected by the reliable protocol.

Claims

1. A reliable replication system comprising:

a processor configured to;

generate replication data, wherein the replication data corresponds to at least a part of file system data to be replicated on a destination replication device;

generate additional verification information based at least in part on at least a portion of the replication data;

include in a first container the replication data and the additional verification information;

include the first container in a second container associated with a reliable protocol; and

an interface coupled to the processor, configured to send the second container including the first container over a communication channel to the destination replication device, wherein the destination replication device is configured to verify the replication data, upon receipt, at least in part by determining whether at least a portion of the second container can be verified using the reliable protocol and in the event that the second container is verified by the reliable protocol, then checking the additional verification information included in the first container to further verify that the replication data does not include data corruption that was introduced by the communication channel and undetected by the reliable protocol, wherein a verification associated with the additional verification information is stronger than a verification associated with the reliable protocol.

2. The system of claim 1, wherein the replication data includes a data segment.

3. The system of claim 1, wherein the replication data includes a data segment reference.

4. The system of claim 1, wherein the verification associated with the reliable protocol for detecting data corruption introduced by the communication channel includes using a reliable protocol checksum;

and the additional verification information includes an additional verification checksum that includes more bits than the reliable protocol checksum.

5. The system of claim 1, wherein the reliable protocol is Transport Control Protocol (TCP).

6. The system of claim 1, wherein the reliable protocol is Transport Control Protocol (TCP), and the additional verification information includes a value that is greater in length than a TCP checksum.

7. The system of claim 1, wherein the additional verification information is generated using an MD5 function.

8. The system of claim 1, wherein the additional verification information is included in a Remote Procedure Call (RPC) argument.

9. The system of claim 1, wherein the additional verification information is included in a Remote Procedure Call (RPC) argument and is determined based at least in part on at least one other RPC argument.

10. The system of claim 1, wherein the first container is a Remote Procedure Call (RPC) packet.

11. The system of claim 1, wherein the second container is a Transport Control Protocol (TCP) packet.

12. A data replication method comprising:

generating replication data, wherein the replication data corresponds to at least a part of file system data to be replicated on a destination replication device;

generating additional verification information based at least in part on at least a portion of the replication data;

including in a first container the replication data and the additional verification information;

including the first container in a second container associated with a reliable protocol; and

sending the second container including the first container over a communication channel to the destination replication device, wherein the destination replication device is configured to verify the replication data, upon receipt, at least in part by determining whether at least a portion of the second container can be verified using the reliable protocol and in the event that the second container is verified by the reliable protocol, then checking the additional verification information included in the first container to further verify that the replication data does not include data corruption that was introduced by the communication channel and undetected by the reliable protocol, wherein a verification associated with the additional verification information is stronger than a verification associated with the reliable protocol.

13. The method of claim 12, wherein the replication data includes a data segment.

14. The method of claim 12, wherein the replication data includes a data segment reference.

15. The method of claim 12, wherein the verification associated with the reliable protocol for detecting data corruption introduced by the communication channel using a reliable protocol checksum;

and the additional verification information includes an additional verification checksum that includes more bits than the reliable protocol checksum.

16. The method of claim 12, wherein the reliable protocol is Transport Control Protocol (TCP).

17. The method of claim 12, wherein the reliable protocol is Transport Control Protocol (TCP), and the additional verification information includes a value that is greater in length than a TCP checksum.

18. The method of claim 12, wherein the additional verification information is generated using an MD5 function.

19. The method of claim 12, wherein the additional verification information is included in a Remote Procedure Call (RPC) argument.

20. The method of claim 12, wherein the additional verification information is included in a Remote Procedure Call (RPC) argument and is determined based at least in part on at least one other RPC argument.

21. The method of claim 12, wherein the first container is a Remote Procedure Call (RPC) packet.

22. The method of claim 12, wherein the second container is a Transport Control Protocol (TCP) packet.

23. A computer program product for data replication, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:

generating replication data, wherein the replication data corresponds to at least a part of file system data to be replicated on a destination replication device;

generating additional verification information based at least in part on at least a portion of the replication data;

including in a first container the replication data and the additional verification information;

including the first container in a second container associated with a reliable protocol; and

sending the second container including the first container over a communication channel to the destination replication device, wherein the destination replication device is configured to verify the replication data, upon receipt, at least in part by determining whether at least a portion of the second container can be verified using the reliable protocol and in the event that the second container is verified by the reliable protocol, then checking the additional verification information included in the first container to further verify that the replication data does not include data corruption that was introduced by the communication channel and undetected by the reliable protocol, wherein a verification associated with the additional verification information is stronger than a verification associated with the reliable protocol.