Least recently used eviction implementation

• US 20060143399A1
• Filed: 12/28/2004
• Published: 06/29/2006
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Wintergerst, Michael, Petev, Petio G.
• Granted Patent: US 7,971,001 B2
• Time in Patent Office: Days
• US Class Current: 711/136
• CPC Class Codes: G06F 12/123 with age lists, e.g. queue, most recently used [MRU] list or least recently used [LRU] list
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning

Abstract

Methods for a treatment of cached objects are described. In one embodiment, management of a region of a cache is configured with an eviction policy plug-in. The eviction policy plug-in includes an eviction timing component and a sorting component, with the eviction timing component including code to implement an eviction timing method, and the eviction timing method to trigger eviction of an object from the region of cache. The sorting component includes code to implement a sorting method to identify an object that is eligible for eviction from said region of cache. The sorting method includes identifying an object for eviction that is cached in the region of cache and that has been used least recently compared to other objects that are cached in the region of cache.

Claims

1. A method, comprising:

configuring management of a region of a cache with an eviction policy plug-in, said eviction policy plug-in comprising an eviction timing component and a sorting component, said eviction timing component comprising code to implement an eviction timing method, said eviction timing method to trigger eviction of an object from said region of cache, said sorting component comprising code to implement a sorting method, said sorting method to identify an object that is eligible for eviction from said region of cache, wherein said sorting method comprises identifying an object for eviction that is cached in said region of cache and that has been used least recently compared to other objects that are cached in said region of cache.

2. The method of claim 1 wherein said object is a member of a shared closure.

3. The method of claim 1 wherein said eviction timing method further comprises, after a threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis.

4. The method of claim 1 wherein said eviction timing method further comprises, after a threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache.

5. The method of claim 1 wherein said eviction timing method further comprises, after a threshold is reached, triggering eviction of one or more objects from said cache region until the usage of said region of cache drops below a specific level.

6. The method of claim 1 wherein said eviction timing method further comprises:

after a first threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis;

after a second threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache; and

,

after a third threshold is reached, triggering eviction of one or more objects from said cache region until the usage of said region of cache drops below a specific level, where, said third threshold corresponds to greater usage of said region of cache than said second threshold and said second threshold corresponds to greater usage of said region of cache than said first threshold.

7. A computing system comprising a machine, said computing system also comprising instructions disposed on a computer readable medium, said instructions capable of being executed by said machine to perform a method, said method comprising:

configuring management of a region of a cache with an eviction policy plug-in, said eviction policy plug-in comprising an eviction timing component and a sorting component, said eviction timing component comprising code to implement an eviction timing method, said eviction timing method to trigger eviction of an object from said region of cache, said sorting component comprising code to implement a sorting method, said sorting method to identify an object that is eligible for eviction from said region of cache, wherein said sorting method comprises identifying an object for eviction that is cached in said region of cache and that has been used least recently compared to other objects that are cached in said region of cache.

8. The computing system of claim 7, wherein said object is a member of a shared closure.

9. The computing system of claim 7, wherein said instructions further cause the machine to perform said method comprising, after a threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis.

10. The computing system of claim 7, wherein said instructions further cause the machine to perform said method comprising, after a threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache.

11. The computing system of claim 7, wherein said instructions further cause the machine to perform said method comprising, after a threshold is reached, triggering eviction of one or more objects from said cache region until a usage of said region of cache drops below a specific level.

12. The computing system of claim 7, wherein said instructions further cause the machine to perform said method further comprising:

after a first threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis;

after a second threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache; and

,

after a third threshold is reached, triggering eviction of one or more objects from said cache region until the usage of said region of cache drops below a specific level, where, said third threshold corresponds to greater usage of said region of cache than said second threshold, and said second threshold corresponds to greater usage of said region of cache than said first threshold.

13. An article of manufacture including program code which, when executed by a machine, causes the machine to perform a method, the method comprising:

configuring management of a region of a cache with an eviction policy plug-in, said eviction policy plug-in comprising an eviction timing component and a sorting component, said eviction timing component comprising code to implement an eviction timing method, said eviction timing method to trigger eviction of an object from said region of cache, said sorting component comprising code to implement a sorting method, said sorting method to identify an object that is eligible for eviction from said region of cache, wherein said sorting method comprises identifying an object for eviction that is cached in said region of cache and that has been used least recently compared to other objects that are cached in said region of cache.

14. The article of manufacture as in claim 13, wherein said object is a member of a shared closure.

15. The article of manufacture as in claim 13, wherein the program code further causes the machine to perform said method of, after a threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis.

16. The article of manufacture as in claim 13, wherein the program code further causes the machine to perform said method of, after a threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache.

17. The article of manufacture as in claim 13, wherein the program code further causes the machine to perform said method of, after a threshold is reached, triggering eviction of one or more objects from said cache region until a usage of said region of cache drops below a specific level.

18. The article of manufacture as in claim 13, wherein the program code further causes the machine to perform said method further comprising:

after a first threshold is surpassed, triggering eviction of an object from said region of cache on a timed basis;

after a second threshold is surpassed, triggering eviction of an object from said region of cache in response to a second object being newly entered into said region of cache; and

,

after a third threshold is reached, triggering eviction of one or more objects from said cache region until the usage of said region of cache drops below a specific level, where, said third threshold corresponds to greater usage of said region of cache than said second threshold, and said second threshold corresponds to greater usage of said region of cache than said first threshold.