METHOD AND APPARATUS FOR USING SELECTIVE ATTRIBUTE ACQUISITION AND CLAUSE EVALUATION FOR POLICY BASED STORAGE MANAGEMENT

• US 20090313297A1
• Filed: 06/12/2008
• Published: 12/17/2009
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hsu, Windsor Wee Sun, Zhou, Pin
• Granted Patent: US 8,266,120 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/40 of multimedia data, e.g. slideshows comprising image and additional audio data retrieval of still image data G06F16/50; retrieval of audio data G06F16/60; retrieval of video data G06F16/70

Abstract

The invention provides a method and apparatus for managing stored data objects. The method includes detecting involved attributes of stored data objects based on object management rules, determining expected data storage management costs for each possible order of attribute acquisition for the detected attributes, detecting an order of attribute acquisition that has a data storage management cost which is minimal or below a predetermined threshold, acquiring the attributes of the stored data objects based on the detected order of attribute acquisition, and executing an object management policy based on the acquired attributes to manage the stored objects at the low cost for object storage, attribute acquisition and policy evaluation.

Claims

1. A method of managing stored data objects, comprising:

detecting involved attributes of a plurality of stored data objects based on a plurality of object management rules;

acquiring the necessary attributes for producing the policy evaluation result with low cost based on selective attribute acquisition; and

executing an object management policy based on the acquired attributes to manage the plurality of stored data objects at reduced cost for object storage, attribute acquisition and policy evaluation.

2. The method of claim 1, wherein selective attribute acquisition comprises:

determining expected data storage management costs for each of a plurality of possible orders of attribute acquisition for the detected attributes;

detecting an order of attribute acquisition that has a data storage management cost below a predetermined threshold; and

acquiring the attributes of the plurality of stored data objects based on said detected order of attribute acquisition.

3. The method of claim 2, wherein the determined expected data storage management costs is defined based on attribute acquisition costs and failure probabilities.

4. The method of claim 1, further comprising:

transforming each rule into a conjunctive normal form; and

analyzing the transformed rules to determine required attribute acquisition costs and failure probabilities and determine a plurality of possible order of attribute acquisition based on the detected attributes.

5. The method of claim 2, further comprising:

adjusting said detected order of attribute acquisition with effective clause information and selective rule clause evaluations of the detected attributes; and

acquiring the attributes of the plurality of stored data objects based on the adjusted order of attribute acquisition.

6. The method of claim 5, wherein selective rule clause evaluations are based on classifying clauses based on attribute stability and attribute value state.

7. The method of claim 4, wherein the required attribute acquisition costs and rule failure probabilities are obtained from system default configuration or user inputs, or dynamically determined based on evaluation history.

8. The method of claim 2, further comprising reducing the plurality of possible orders of attribute acquisition based on the heuristics.

9. The method of claim 1, further comprising:

identifying shared attributes used by the plurality of object management rules;

classifying shared attributes based on their change frequencies; and

storing the never or rarely changed shared attributes for acquiring them only once and using them for the plurality of object management rules.

10. An apparatus for managing object storage, comprising:

a policy engine module configured to receive a plurality of cached attributes, clause results, change logs and future status for the plurality of stored data objects from a database;

a policy analyzer module configured to analyze the object management policy to detect involved attributes of the plurality of stored data objects, to identify acquisition costs and clause failure probabilities required to execute the object management policy and to determine attribute acquisition order that has a data storage management cost which is minimal or below a predetermined threshold; and

an information acquisition module configured to acquire the attributes of the plurality of stored data objects from the repository based on the low cost attribute acquisition order,

wherein the policy engine module is further configured to execute an object management policy based on the acquired attributes to manage the plurality of stored data objects at the low cost for object storage, attribute acquisition and policy evaluation.

11. The apparatus of claim 10, wherein the policy analyzer module is further configured to:

classify clauses based on its attribute and value state; and

send the clause classification information to the policy engine module for storing clause results and/or change logs and/or future status in a database based on clause classifications.

12. The apparatus of claim 10, wherein the policy analyzer module is further configured to:

identify shared attributes used by the plurality of object management rules;

classify shared attributes based on their change frequencies; and

send the shared attribute classification information to the information acquisition module for storing constant and stable shared attributes in a database.

13. A computer program product for managing stored data objects comprising a computer usable medium including a computer readable program, wherein the computer readable program when executed on a computer causes the computer to:

detect involved attributes of a plurality of stored data objects based on a plurality of object management rules;

acquire the necessary attributes for producing the policy evaluation result with low cost based on selective attribute acquisition; and

execute an object management policy based on the acquired attributes to manage the plurality of stored data objects at reduced cost for object storage, attribute acquisition and policy evaluation.

14. The computer program product of claim 13, wherein the computer readable program when executed on the computer further causes the computer to:

determine expected data storage management costs for each of a plurality of possible orders of attribute acquisition for the detected attributes;

detect an order of attribute acquisition that has a data storage management cost below a predetermined threshold; and

acquire the attributes of the plurality of stored data objects based on said detected order of attribute acquisition.

15. The computer program product of claim 14, wherein the determined expected data storage management costs is defined based on attribute acquisition costs and failure probabilities.

16. The computer program product of claim 13, wherein the computer readable program when executed on the computer further causes the computer to:

transform each rule into a conjunctive normal form; and

analyze the transformed rules to determine required attribute acquisition costs and failure probabilities and determine a plurality of possible order of attribute acquisition based on the detected attributes.

17. The computer program product of claim 14, wherein the computer readable program when executed on the computer further causes the computer to:

adjust said detected order of attribute acquisition with effective clause information and selective rule clause evaluations of the detected attributes; and

acquire the attributes of the plurality of stored data objects based on the adjusted order of attribute acquisition.

18. The computer program product of claim 16, wherein the required attribute acquisition costs and rule failure probabilities are obtained from system default configuration or user inputs, or dynamically determined based on evaluation history.

19. The computer program product of claim 14, wherein the computer readable program when executed on the computer further causes the computer to reduce the plurality of possible orders of attribute acquisition based on the heuristics.

20. The computer program product of claim 13, wherein the computer readable program when executed on the computer further causes the computer to:

identify shared attributes used by the plurality of object management rules;

classify shared attributes based on their change frequencies; and

store the never or rarely changed shared attributes for acquiring them only once and using them for the plurality of object management rules.