Synchronization of database data

• US 20050125459A1
• Filed: 11/18/2004
• Published: 06/09/2005
• Est. Priority Date: 04/25/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Piispanen, Jussi, Mettala, Riku, Sutinen, Ari, Sahinoja, Mikko
• Granted Patent: US 7,555,303 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A method of arranging synchronization of databases, the method comprising the steps of establishing a transport layer connection for synchronization between a first and a second device which synchronize databases. During initialization of synchronization a first update identifier, which is stored at least in the first device and describes the latest synchronization event the devices have performed in the databases, and a second update identifier, which is defined by the first device and describes the present synchronization, are transmitted from the first device to the second device. The second update identifier is stored in the first and the second device. The contents of the first update identifiers stored in the devices are updated in the first and the second device if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

Claims

1-13. -13 (canceled)

14. A method for arranging synchronization of databases, the method comprising the steps of:

establishing a transport connection for synchronizing databases,

transmitting an update identifier, which describes an earlier synchronization event that has been performed between the databases, by using said transport connection, and

storing an update identifier describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.

15. A method according to claim 14, wherein a first update identifier, which describes the earlier synchronization event that has been performed between the databases and a second update identifier, which is defined by a first device and describes the present synchronization are transmitted from the first device to a second device, and

contents of stored first update identifiers are updated with the contents of a second update identifier if synchronization has been performed and after this said transport connection has been ended substantially properly.

16. A method according to claim 15, which further comprises the steps of:

comparing the first update identifier received in the second device with the first update identifier stored in the second device,

performing synchronization in the requested manner if the first received update identifier corresponds to the first stored update identifier,

synchronizing all data units of the databases if the first received update identifier does not correspond to the first stored update identifier.

17. A method according to claim 16, which further comprises the steps of:

transmitting the first stored update identifier from the second device to the first device,

comparing also the first received update identifier with the first stored update identifier in the first device.

18. A method according to claim 14, wherein the update identifier indicates date and time.

19. A method according to claim 15, wherein the first update identifier is the Last anchor of synchronization and the second update identifier the Next anchor.

20. A method according to claim 14, wherein said transport connection is a logical connection in accordance with the HTTP protocol, and

said transport connection has been ended properly if a ‘

HTTP request’

message has been transferred after synchronization and a ‘

HTTP status response’

message related to the ‘

HTTP request’

message has been transmitted and received.

21. A synchronization system for synchronizing databases, the system comprising a first device and a second device which perform synchronization and are configured to

establish a transport connection between the first device and the second device for performing synchronization,

transmit a first update identifier, which describes the latest synchronization event the first and the second device have performed in the databases, from the first device to the second device and a second update identifier, which is defined by the first device and describes an earlier synchronization,

store said second update identifier, and

update the contents of the first update identifiers in the devices with the contents of said second update identifier if synchronization has been performed and after this said transport connection has been ended substantially properly.

22. A synchronization system according to claim 21, wherein the second device is arranged to compare the first update identifier received with the first update identifier stored in the second device,

the first and the second device are arranged to perform synchronization in the requested manner if the first received update identifier corresponds to the first stored update identifier, or

the first device and the second device are configured to synchronize all data units of the databases if the first received update identifier does not correspond to the first stored update identifier.

23. A communications device comprising:

means for establishing a transport connection for synchronizing databases,

means for transmitting, by using said transport connection, an update identifier describing an earlier synchronization event that has been performed between the databases, and

means for storing an update identifier describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.

24. A communications device according to claim 23, wherein the communications device is configured to:

transmit a first update identifier, which describes the earlier synchronization event that has been performed between the databases, and a second update identifier, which is defined by the communications device and describes the present synchronization, and

update contents of the stored first update identifier with the contents of the second update identifier if synchronization has been performed and after this said transport connection has been ended substantially properly.

25. A communications device according to claim 24, wherein the communications device is configured to store said second update identifier.

26. A communications device according to claim 23, wherein the communications device is configured to establish said transport connection to at least one other device.

27. A communications device according to claim 24, wherein the communications device is configured to receive a first update identifier stored by the other device, and the communications device is configured to compare also the first received update identifier with the first stored update identifier.

28. A communications device according to claim 23, wherein the update identifier indicates date and time.

29. A communications device according to claim 23, wherein said transport connection is a logical connection in accordance with the HTTP protocol, and

the communications device is configured to determine that said transport connection has been ended properly if a ‘

HTTP request’

message has been transmitted after synchronization and a ‘

HTTP status response’

message related to the ‘

HTTP request’

message has been received.

30. A communications device according to claim 23, wherein the communications device is configured to transmit the update identifier to the other device during initialization of synchronization.

31. A communications device comprising:

means for establishing a transport connection for synchronizing databases,

means for transmitting, by using said transport connection, a timestamp describing an earlier synchronization event that has been performed between the databases, and

means for storing a timestamp describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.

32. A synchronization device comprising:

means for establishing a transport connection for synchronizing databases,

means for receiving, by using said transport connection, an update identifier describing an earlier synchronization event that has been performed between the databases, and

means for storing an update identifier describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.

33. A synchronization device according to claim 32, wherein the synchronization device is configured to:

receive a first update identifier and a second update identifier, the first update identifier describing the latest synchronization event that has been performed in the databases, and the second update identifier describing the present synchronization,

store said second update identifier, and

update a first update identifier stored in the synchronization device with the contents of said received second update identifier if synchronization has been performed and after this said transport connection has been ended substantially properly.

34. A synchronization device according to claim 33, which also comprises

means for comparing the first update identifier received with the first update identifier stored in said synchronization device,

means for performing synchronization in the manner requested by the other device if the first received update identifier corresponds to the first stored update identifier, and

means for synchronizing data units of all databases if the first received update identifier does not correspond to the first stored update identifier.

35. A synchronization device according to claim 34, wherein the synchronization device is configured to transmit the first update identifier stored in the synchronization device to at least one other device.

36. A synchronization device according to claim 32, wherein the synchronization device is configured to establish said transport connection to at least one other device, and

the synchronization device is configured to receive the update identifier from other device during initialization of synchronization.

37. A synchronization device according to claim 32, wherein the update identifier indicates date and time.

38. A synchronization device according to claim 32, wherein said transport connection is a logical connection in accordance with the HTTP protocol, and

the synchronization device is configured to determine that said transport connection has been ended properly if a ‘

HTTP request’

message has been received after synchronization and a ‘

HTTP status response’

message related to the ‘

HTTP request’

message has been transmitted.

39. A computer program product loadable into the memory of a communications device and comprising a code which is executable in the communications device causing the communications device to:

transmit, by using a transport connection for synchronizing databases, an update identifier describing an earlier synchronization event that has been performed between the databases, and

store an update identifier describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.

40. A computer program product loadable into the memory of a computer functioning as a synchronization device and comprising a code which is executable in the synchronization device causing the synchronization device

receive, by using a transport connection for synchronizing databases, an update identifier describing an earlier synchronization event that has been performed between the databases, and

store an update identifier describing a current synchronization event if synchronization has been performed and after this said transport connection has been ended substantially properly.