Urgent replication facility

• US 7,200,847 B2
• Filed: 05/23/2002
• Issued: 04/03/2007
• Est. Priority Date: 07/01/1996
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Contorer, Aaron M., Straube, Dave D., Miller, Arnold S., Misra, Pradyumna K., Raman, Balan S., Seaman, Michael R. C.
• Primary Examiner(s): Nguyen; Van H.
• Application Number:
  US10/154,014
• Publication Number:
  US 20020144252A1
• Time in Patent Office: 1,776 Days
• Field of Search: 719/313, 719/315, 717/170, 707/201, 707/203, 707/8, 707/10, 709/206, 709/207
• US Class Current: 719/313
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 9/54 Interprogram communication

Abstract

A system and method for expediting the replication of at least one specified object to a replica in a distributed computer system. A source object of a source replica determines that it has an urgent change to propagate through the distributed system, and informs a replication facility at the source replica of the urgent change. The facility extracts, or is provided with, the change information from that object, and the source replica communicates information representative of the change to a destination replica. A replication facility at the destination replica provides the change information to a destination replica object, which uses the information to make itself consistent with the source replica object.

Claims

1. In a distributed computer system, a method of expediting the replication a source object in a source computer to a destination replica object in a destination replica in the system wherein the state of the source object has changed from a first to a second state, comprising the steps of:

identifying, by the source computer, a difference in the changed source object;

transmitting, by the source computer, the difference to the destination replica;

receiving, by the destination replica, the transmitted difference;

applying, by the destination replica, the difference to the destination replica object;

extracting destination change information from the destination replica object;

transmitting information to a second destination replica corresponding to the destination change information;

receiving the transmitted information at the second destination replica;

extracting the change information from the received information at the second destination replica;

providing the change information to a replica object of the second destination replica; and

applying the destination change information to the replica object of the second destination replica.

2. The method of claim 1 wherein the source object initiates the identifying step.

3. The method of claim 1, further comprising the step of applying the difference to the destination replica object such that the destination replica object is consistent with the changed source object.

4. The method of claim 1, wherein the step of identifying includes invoking a method of a replication framework.

5. The method of claim 1, wherein the step of transmitting the difference includes a duplication of the entire source object.

6. The method of claim 1, wherein the step of identifying the difference comprises the source object generating differencing information.

7. The method of claim 1, further comprising the steps of:

when communication between the source computer and the destination replica is unavailable, storing the difference with timestamp value at the source computer;

then after communication between the source computer and the destination replica becomes available, and if the difference corresponds to a relatively recent change, then expediting the replication of the source object.

8. A commuter readable medium having computer executable instructions for a method of expediting the replication of a source object in a source computer to a destination replica object in a destination replica in the system wherein the state of the source object has changed from a first to a second state, the steps comprising:

identifying, by the source computer, a difference in the changed source object;

transmitting, by the source computer, the difference to the destination replica;

receiving, by the destination replica, the transmitted difference;

applying, by the destination replica, the difference to the destination replica object;

extracting destination change information from the destination replica object;

transmitting information to a second destination replica corresponding to the destination change information;

receiving the transmitted information at the second destination replica;

extracting the change information from the received information at the second destination replica;

providing the change information to a replica object of the second destination replica; and

applying the destination change information to the replica object of the second destination replica.

9. The computer readable medium of claim 8, further comprising the steps of:

when communication between the source computer and the destination replica is unavailable, storing the difference with a timestamp value at the source computer;

then after communication between the source computer and the destination replica becomes available, and if the difference corresponds to a relatively recent change, then expediting the replication of the source object.

10. The computer-readable medium of claim 8 wherein the source object initiates the identifying step.

11. The computer readable medium of claim 8, further comprising the step of applying the difference to the destination replica object such that the destination replica object is consistent with the changed source object.

12. The computer readable medium of claim 8, wherein the step of identifying includes invoking a method of a replication framework.

13. The computer readable medium of claim 8, wherein the step of transmitting the difference includes a duplication of the entire source object.

14. The computer readable medium of claim 8, wherein the step of identifying the difference comprises the source abject generating differencing information.

15. A distributed computer system that expedites the replication of a source object in a source node to a destination replica object in a destination node in the system, wherein the state of the source object has changed from a first to a second state, the system comprising:

a source node that performs the steps of;

identifying a difference in the changed source object;

transmitting the difference;

a destination node that performs the steps of;

receiving the transmitted difference;

applying the difference to the destination replica object;

extracting destination change information from the destination replica object;

transmitting information corresponding to the destination change information; and

a second destination node that performs the steps of;

receiving the transmitted information;

extracting the destination change information from the received information;

providing the change information to a replica object of the second destination node;

applying the destination change information to the replica object of the second destination node.

16. The computer system of claim 15, wherein the source object initiates the identifying step.

17. The computer system of claim 15, wherein the source node further performs the step of:

when communication between the source node and the destination node is unavailable, storing the difference with a timestamp value at the source node;

then after communication between the source node and the destination node becomes available, and if the difference corresponds to a relatively recent change, then expediting the replication of the source object.

18. The computer system of claim 15, wherein the step of identifying includes invoking a method of a replication framework.

19. The computer system of claim 15, wherein the step of transmitting the difference includes a duplication of the entire source object.

20. The computer system of claim 15, wherein the step of identifying the difference comprises the source object generating differencing information.