System managed logging of objects to speed recovery processing

• US 5,625,820 A
• Filed: 07/03/1996
• Issued: 04/29/1997
• Est. Priority Date: 09/30/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ricard, Gary R., Youngren, Larry W., Hermsmeier, David L., Vriezen, John J.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Lintz, Paul R.
• Application Number:
  US08/674,941
• Time in Patent Office: 300 Days
• Field of Search: 395/618, 395/182.14
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery

Abstract

System control over the logging of objects in order to meet the user specified recovery requirements. Under the fixed recovery time environment, the user chooses a length of time to be spent on object recovery, and the system dynamically manages the logging of objects to meet this time. The shorter the time the user chooses, the more objects the system will log, and the more performance degradation there will be as a result of the logging at run-time. The user may partition storage into Auxiliary Storage Pools (ASPs), which are groups of non-volatile storage, and then specify the recovery time on a per ASP basis. Under the minimal impact environment, the system dynamically manages the objects to be logged such that the object logging has a minimal impact on run-time performance.

Claims

1. An object recovery mechanism in a computer system, comprising:

means for determining and maintaining rebuild information representative of an amount of time associated with each respective object in a plurality of objects that would be required to rebuild said respective object in the event data contained in said object becomes lost;

mean for selectively logging changes to a subset of said plurality of objects in a non-volatile log, wherein said subject of said plurality of objects is selected for logging based on said rebuild information; and

means for recovering said subset of said plurality of objects from said logged changes recorded in said non-volatile log in the event data contained in said object becomes lost.

2. An computer system comprising:

at least one central processing unit (CPU);

main memory coupled to said CPU;

nonvolatile storage coupled to said CPU;

means for determining and maintaining rebuild information representative of an amount of time associated with each respective object in a plurality of objects that would be required to rebuild said respective object in the event data contained in said object becomes lost;

mean for selectively logging changes to a subset of said plurality of objects in a log contained in said non-volatile storage, wherein said subset of said plurality of objects is selected for logging based on said rebuild information; and

means for recovering said subset of said plurality of objects from said logged changes recorded in said non-volatile log in the event data contained in said objects becomes lost.

3. A method of object recovery in a computer system, comprising the machine executed steps of:

determining and maintaining rebuild information representative of an amount of time associated with each respective object in a plurality of objects that would be required to rebuild said respective object in the event data contained in said object becomes lost;

selectively logging changes to a subset of said plurality of objects in a non-volatile log, wherein said subset of said plurality of objects is selected for logging based on said rebuild information; and

recovering said subset of said plurality of objects from said logged changes recorded in said non-volatile log in the event data contained in said objects becomes lost.