Method and system for using a sync key

• US 20050216441A1
• Filed: 05/16/2005
• Published: 09/29/2005
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Thomas, Edward Eric, Flanagin, Stephen D.
• Granted Patent: US 7,228,321 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A method and system for synchronization of data stores is described. A synchronization initiator sends a sync key to a synchronization partner requesting to synchronize to some checkpoint. An integer is used as the sync key. When the sent sync key is zero the synchronization partner performs an initial synchronization. When the sent sync key is a value other than zero, the synchronization partner attempts to synchronize to the desired state. The value of the sync key is incremented only upon successful synchronization. A sync server can also include a sync key with change update notifications sent to a sync client, which the client can use to determine if the update notification is a valid update from the current sync state or is a delayed and obsolete update that should be discarded.

Claims

1-20. -20. (canceled)

21. A computer-readable medium having computer-executable instructions for synchronization, the instructions comprising:

receiving a sync key;

determining a desired synchronization state from the sync key; and

attempting to synchronize a client to the desired synchronization state.

22. The computer-readable medium of claim 21, further comprising updating the sync key when the synchronization is successful.

23. The computer-readable medium of claim 21, wherein determining the desired synchronization state from the sync key further includes comparing the sync key to a second sync key and setting the desired synchronization based on the comparison.

24. The computer-readable medium of claim 23, further comprising updating at least one of:

the sync key and the second sync key.

25. The computer-readable medium of claim 23, wherein setting the desired synchronization based on the comparison includes at least one of:

setting the desired synchronization state to an initial synchronization and setting the desired synchronization state to a stored synchronization state.

26. The computer-readable medium of claim 21, further comprising incrementing a value of the sync key when the synchronization is successful.

27. A computer synchronization system, the system comprising:

a sync key means, wherein the sync key means is configured to indicate a synchronization state;

an initiator means, wherein the initiator means is configured to transmit the sync key means; and

a partner means, wherein the partner means is configured to receive the sync key means from the initiator means and determine a desired synchronization state of the initiator means from the sync key means.

28. The system of claim 27, wherein the partner means is further configured to set the desired synchronization state based on a determined value of the sync key means.

29. The system of claim 27, wherein the partner means is further configured to determine when the sync key means is valid.

30. The system of claim 29, wherein the partner means is further configured to determine when a partner sync key exists related to the sync key means and when so:

determining a previously stored value of the partner sync key; and

comparing the value of the partner sync key to the value of the sync key means.

31. The system of claim 27, wherein the partner means is further configured to determine when the desired synchronization state is an initial synchronization state based on the sync key means.

32. The system of claim 27, wherein the partner means is further configured to determine when the desired synchronization state is another valid synchronization state based on a value of the sync key means.

33. The system of claim 27, wherein the initiator means is further configured to determine when a synchronization is successful and update the sync key means on the initiator means.

34. The system of claim 27, wherein the partner means is further configured to determine when a synchronization is successful and update the sync key means on the partner means.

35. The system of claim 27, wherein the partner means is further configured to determine when the desired synchronization state is another valid synchronization state based on the sync key means and determine when the sync key means corresponds to a stored synchronization checkpoint.

36. The system of claim 27, wherein the sync key means includes an integer.

37. A modulated data signal having data fields encoded thereon for synchronizing computing devices, the modulated data signal comprising:

a first date field having a sync key, wherein the sync key is configured to;

identify a synchronization state of an initiator to synchronize from by transmitting the first data field over a communication channel to a synchronization partner.

38. The modulated data signal of claim 37, wherein the sync key is further configured to update when a synchronization partner is successfully updated.

39. The computer-readable medium of claim 37, wherein an integer associated with the sync key is incremented when a synchronization partner is successfully updated.

40. The computer-readable medium of claim 37, wherein the sync key includes at least one of:

a bit, a float, a character and an integer.