Ranging scalable time stamp data synchronization

• US 9,256,658 B2
• Filed: 07/18/2011
• Issued: 02/09/2016
• Est. Priority Date: 07/12/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Castaneda, Frank J.
• Primary Examiner(s): PARK, GRACE A
• Application Number:
  US13/184,743
• Publication Number:
  US 20110276536A1
• Time in Patent Office: 1,667 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

Embodiments of the present invention address deficiencies of the art in respect to time stamp based data synchronization and provide a method, system and computer program product for scalable, ranging time stamp based data synchronization. In an embodiment of the invention, a ranging time stamp synchronization method can include computing a time range for a specified time, and producing time stamp synchronization anchors using the time range for each of the anchors. Optionally, a drift value can be computed for the time range and the computing and producing steps can be repeated when the drift value exceeds a threshold. Finally, the anchors can be used to determine whether to update data items in a remote data source in the remote host computing platform with data items from a primary data source in the primary host computing platform.

Claims

1. A method for performing data synchronization between a primary data source in a primary host computing platform and a remote data source in a remote host computing platform, comprising:

receiving a request for data synchronization for updated data falling within a specified time range;

computing ranging time stamp synchronization anchors based on the specified time range, wherein the ranging time stamp synchronization anchors correspond to a minimum value and a maximum value determined based on the specified time range, a time synchronization error between the primary host computing platform and the remote host computing platform, and also an offset being a sum of a time retrieved from the remote host computing platform, the time synchronization error, and also an accuracy of a clock of the primary host computing platform; and

performing data synchronization using the computed ranging time stamp synchronization anchors without relying upon a third party time source common to both the primary host computing platform and the remote host computing platform.

2. The method of claim 1, wherein the specified time range is between a first time and a second time, and the ranging time stamp synchronization anchors include a first ranging time stamp synchronization anchor corresponding to the first time and a second ranging time stamp synchronization anchor corresponding to the second time.

3. The method of claim 2, wherein the first ranging time stamp synchronization anchor includes a first minimum value and a first maximum value, and the second ranging time stamp synchronization anchor includes a second minimum value and a second maximum value.

4. The method of claim 3, wherein the data synchronization is performed for updated data falling within a time range between the first minimum value and the second maximum value.

5. The method of claim 1, wherein the time synchronization error is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a known accuracy for a clock in the primary host computing platform.

6. The method of claim 1, wherein the offset is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a difference between a retrieved time from the remote host computing platform and a time when the retrieved time is received at the primary host computing platform.

7. The method of claim 1, further comprising:

calculating a drift value indicating a rate at which a clock in the primary host computing platform deviates from a clock on the remote host computing platform.

8. The method of claim 1, wherein the minimum time is determined by selecting a time value between the specified time range and adding the selected time value to the offset and subtracting the time synchronization error and wherein the maximum time is determined by an addition of the selected time value to the offset and also to the time synchronization error.

9. A ranging time stamp data synchronization system, comprising:

a primary data source disposed in a primary host computing platform;

a remote data source disposed in a remote host computing platform communicatively linked to the primary host computing platform;

data synchronization logic coupled to the primary data source for performing data synchronization between the primary data source in the primary host computing platform and the remote data source in the remote host computing platform; and

a ranging time stamp synchronization processor coupled to the data synchronization logic, the processor being configured to

receive a request for data synchronization for updated data falling within a specified time range;

compute ranging time stamp synchronization anchors based on the specified time range, wherein the ranging time stamp synchronization anchors correspond to a minimum value and a maximum value determined based on the specified time range, a time synchronization error between the primary host computing platform and the remote host computing platform, and also an offset being a sum of a time retrieved from the remote host computing platform, the time synchronization error, and also an accuracy of a clock of the primary host computing platform; and

perform data synchronization using the computed ranging time stamp synchronization anchors without relying upon a third party time source common to both the primary host computing platform and the remote host computing platform.

10. The system of claim 9, wherein the specified time range is between a first time and a second time, and the ranging time stamp synchronization anchors include a first ranging time stamp synchronization anchor corresponding to the first time and a second ranging time stamp synchronization anchor corresponding to the second time.

11. The system of claim 10, wherein the first ranging time stamp synchronization anchor includes a first minimum value and a first maximum value, and the second ranging time stamp synchronization anchor includes a second minimum value and a second maximum value.

12. The system of claim 11, wherein the data synchronization is performed for updated data falling within a time range between the first minimum value and the second maximum value.

13. The system of claim 9, wherein time synchronization error is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a known accuracy for a clock in the primary host computing platform.

14. The system of claim 9, wherein the offset is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a difference between a retrieved time from the remote host computing platform and a time when the retrieved time is received at the primary host computing platform.

15. A computer program product comprising a non-transitory computer usable storage medium having stored therein computer usable program code for performing data synchronization between a primary data source in a primary host computing platform and a remote data source in a remote host computing platform, the computer usable program code which for when executed by a computer hardware device, causes the computer hardware device to perform

receiving a request for data synchronization for updated data falling within a specified time range;

computing ranging time stamp synchronization anchors based on the specified time range, wherein the ranging time stamp synchronization anchors correspond to a minimum value and a maximum value determined based on the specified time range, a time synchronization error between the primary host computing platform and the remote host computing platform, and also an offset being a sum of a time retrieved from the remote host computing platform, the time synchronization error, and also an accuracy of a clock of the primary host computing platform; and

performing data synchronization using the computed ranging time stamp synchronization anchors without relying upon a third party time source common to both the primary host computing platform and the remote host computing platform.

16. The computer program product of claim 15, wherein the specified time range is between a first time and a second time, and the ranging time stamp synchronization anchors include a first ranging time stamp synchronization anchor corresponding to the first time and a second ranging time stamp synchronization anchor corresponding to the second time.

17. The computer program product of claim 16, wherein the first ranging time stamp synchronization anchor includes a first minimum value and a first maximum value, and the second ranging time stamp synchronization anchor includes a second minimum value and a second maximum value.

18. The computer program product of claim 17, wherein the data synchronization is performed for updated data falling within a time range between the first minimum value and the second maximum value.

19. The computer program product of claim 15, wherein the time synchronization error is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a known accuracy for a clock in the primary host computing platform.

20. The computer program product of claim 15, wherein the offset is computed by

obtaining a lapsed period of time between a request for time from the remote host computing platform and receiving the time from the remote host computing platform;

halving the lapsed period to produce a time distance to the remote host computing platform; and

adding the time distance to a difference between a retrieved time from the remote host computing platform and a time when the retrieved time is received at the primary host computing platform.