Object replication using information quality of service

• US 20060106894A1
• Filed: 11/03/2004
• Published: 05/18/2006
• Est. Priority Date: 11/03/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Richardson, James P.
• Granted Patent: US 7,596,585 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

A database replication function for a local object and one or more destination objects, where one or more local applications make requests to the source objects is disclosed. A request logging function records requests sent by the one or more local applications into a memory log. An update propagation function determines which source object states must be propagated to one or more destination objects based on information quality of service accuracy requirements.

Claims

1. A database replication function for a local object and one or more destination objects, where one or more local applications make requests to the source object, the database replication function comprising:

a request logging function adapted to record a sequence of requests sent by the one or more applications to the source object; and

an update propagation function, wherein the update propagation function determines which source object states to propagate to the one or more destination objects, based on information quality of service accuracy requirements.

2. The database replication function of claim 1, wherein the request logging function is further adapted to filter out requests that do not cause a state change in the source object and to record a sequence of requests sent by the one or more applications to the source object that do cause a state change in the source object.

3. The database replication function of claim 1, wherein the update propagation function determines which source object states to propagate by determining whether the present source object state meets a propagation condition.

4. The database replication function of claim 3, wherein the information quality of service accuracy requirements include the parameters (Δ

s, Δ

t) and wherein the propagation condition is met if the magnitude of the source object state change from s_i to s_j is greater than or equal to the parameter Δ

s, and the state s_j has existed on the source object for a time greater than or equal to Δ

t without being propagated to the destination object.

5. The database replication function of claim 4, where Δ

t is a function of Δ

s such that larger source object state changes are propagated sooner than relatively smaller changes.

6. The database replication function of claim 4, wherein the magnitude of the source object state change from s_i to s_j is measured using a distance function.

7. The database replication function of claim 4, wherein the update propagation function propagates a source object state to the destination object by outputting a sequence of updates based on a sequence of requests from the request logging function.

8. The database replication function of claim 7, wherein the update propagation function applies a compression algorithm that transforms the sequence of requests from the request logging function into a compressed sequence of requests to produce the sequence of updates.

9. The database replication function of claim 8, wherein the compression algorithm applies a set of compression transformations to the sequence of requests from the request logging function interactively.

10. The database replication function of claim 9, wherein the compression algorithm reorders one or more commutative requests.

11. The database replication function of claim 7, wherein the update propagation function further propagates a source object state to the destination object based on information quality of service timing requirements.

12. The database replication function of claim 11, wherein the update propagation function is executed cyclically, with a cycle period chosen so that the information quality of service timing requirements are not exceeded.

13. The database replication function of claim 1, wherein the source database and the destination database are both container objects.

14. A database system comprising:

a source object, the source object having a container object structure, the source object further having one or more contained objects;

one or more destination objects, the one or more destination object having the same container object structure as the source object;

one or more local applications;

the one or more local applications adapted to make requests to the source object;

a request logging function adapted to record a sequence of requests sent by the one or more applications to the source object;

an update propagation function, wherein the update propagation function determines which source object states to propagate to the one or more destination objects, based on information quality of service accuracy requirements.

15. The database system of claim 14, wherein the request logging function is further adapted to filter out requests that do not cause a state change in the source object and records a sequence of requests sent by the one or more applications to the source object that do cause a state change in the source object.

16. The database system of claim 14, wherein the update propagation function determines which source object states must be propagated by determining whether one or more of the contained objects of the source object state meet a propagation condition,

wherein the information quality of service accuracy requirements include parameters (Δ

s, Δ

t) for one or more of the contained objects,

wherein the propagation condition for a contained object is met if the magnitude of the contained object state change from s_i to s_j is greater than or equal to the parameter Δ

s, and the state s_j has existed on the contained object for a time greater than or equal to Δ

t without being propagated to the destination object, and

wherein the magnitude of the contained object state change from s_i to s_j is measured using a distance function.

17. The database system of claim 16, wherein the update propagation function propagates a source object state to the destination object by outputting a sequence of updates based on a sequence of requests from the request logging function,

wherein the update propagation function transforms the sequence of requests from the request logging function into a partially-ordered set of requests based on a container specification,

wherein the update propagation function applies a compression algorithm that transforms the partially-ordered set of requests into a compressed sequence of requests to produce the sequence of updates, and

wherein the update propagation function is executed cyclically, with a cycle period chosen so that the information quality of service timing requirements are not exceeded.

29. The database system of claim 14, further comprising:

an update reception function, wherein the update reception function is adapted to update the source object based on object states received from the one or more destination objects.

18. A method for propagating database updates, the method comprising:

logging requests made to a source object by one or more applications;

determining the magnitude of a source object state change since the time of the most recent previous update propagation;

determining if the magnitude of the source object state change is greater than or equal to an information quality of service accuracy parameter Δ

s;

determining if the present source object state has existed on the source object for a time greater than or equal to an information quality of service accuracy parameter Δ

t without being propagated to the destination object; and

propagating a sequence of updates based on the logged requests to one or more destination objects, when the magnitude of the source object state change is greater than or equal to Δ

s and the present source object state has existed on the source object for a time greater than or equal to Δ

t without being propagated to the one or more destination objects.

19. The method of claim 18, further comprising:

applying a compression algorithm that transforms the logged requests into a compressed sequence of requests to produce the sequence of updates.

20. The method of claim 18, wherein the magnitude of the source object state change is determined by a distance function.

21. The method of claim 18, further comprising:

determining how long of a duration of time is tolerable to propagate the source object state to the one or more destination objects once the magnitude of the source object state change is greater than or equal to Δ

s, and wherein the propagating a sequence of updates is completed with that duration of time.

22. A method for propagating database updates, the method comprising:

logging requests made to a source object by one or more applications;

periodically determining if the magnitude of a source object state change, since the time of the most recent previous update propagation, is greater than or equal to an information quality of service accuracy parameter Δ

s and if the present source object state has existed on the source object for a time greater than or equal to an information quality of service accuracy parameter Δ

t without being propagated to the destination object;

when the magnitude of the source object state change is greater than or equal to Δ

s and the present source object state has existed on the source object for a time greater than or equal to Δ

t without being propagated to the one or more destination objects, applying a compression algorithm that transforms the logged requests into a compressed sequence of requests; and

propagating the compressed sequence of request to one or more destination objects, wherein the cycle period for periodically determining the magnitude of the source object state change is chosen so that information quality of service timing requirements are not exceeded.

23. A method for propagating database updates, the method comprising:

logging requests made to a source object by one or more applications;

determining the magnitude of a source object state change since the time of the most recent previous update propagation;

determining if the magnitude of the source object state change is greater than or equal to an information quality of service accuracy parameter Δ

s; and

when the magnitude of the source object state change is greater than or equal to Δ

s, propagating a sequence of updates based on the logged requests to one or more destination databases.

24. A method for propagating database updates, the method comprising:

logging requests made to a source object by one or more applications;

determining the magnitude of a source object state change since the time of the most recent previous update propagation;

determining if the magnitude of the source object state change is greater than or equal to an information quality of service accuracy parameter Δ

s;

when the magnitude of the source object state change is greater than or equal to Δ

s, applying a compression algorithm that transforms the logged requests into a compressed sequence of requests to produce the sequence of updates; and

propagating the compressed sequence of updates based on the logged requests to one or more destination databases.

25. A computer-readable medium having computer-executable instructions for performing a method for propagating database updates, the method comprising:

logging requests made to a source object by one or more applications;

determining the magnitude of a source object state change since the time of the most recent previous update propagation;

determining if the magnitude of the source object state change is greater than or equal to an information quality of service accuracy parameter Δ

s;

determining if the present source object state has existed on the source object for a time greater than or equal to an information quality of service accuracy parameter Δ

t without being propagated to the destination object; and

propagating a sequence of updates based on the logged requests to one or more destination databases, if the magnitude of the source object state change is greater than or equal to Δ

s and the present source object state has existed on the source object for a time greater than or equal to Δ

t without being propagated to the one or more destination objects.

26. The method of claim 25, further comprising:

applying a compression algorithm that transforms the logged requests into a compressed sequence of requests to produce the sequence of updates.

27. The method of claim 25, wherein the magnitude of the source object state change is determined by a distance function.

28. The method of claim 25, further comprising:

determining how long of a duration of time is tolerable to propagate the source object state to the one or more destination objects once the magnitude of the source object state change is greater than or equal to Δ

s, and wherein the propagating a sequence of updates is completed with that duration of time.