Main concept for common cache management

• US 20060143389A1
• Filed: 12/28/2004
• Published: 06/29/2006
• Est. Priority Date: 12/28/2004
• Status: Abandoned Application

• Current Assignee: SAP AG (SAP SE)
• Original Assignee: SAP AG (SAP SE)
• Inventors: Wintergerst, Michael, Kilian, Frank, Petev, Petio, Rohland, Hans-Christoph
• Application Number:
  US11/025,482
• Publication Number:
  US 20060143389A1
• Time in Patent Office: Days
• US Class Current: 711/130
• CPC Class Codes: G06F 12/084 with a shared cache

Abstract

A system and method of common cache management. Plural VMs each have a cache infrastructure component used by one or more additional components within each VM. An external cache is provided and shared by the components of each of the VMs. In one embodiment, a shared external memory is provided and populated by the VMs in the system with cache state information responsive to caching activity. This permits external monitoring of caching activity in the system.

Claims

1. A system comprising:

a first virtual machine (VM) and a second VM, each VM having a cache infrastructure component, each cache infrastructure component to be used by at least one additional component within the respective VM; and

a cache external to either VM and shared by both VM'"'"'s.

2. The system of claim 1 further comprising:

a shared memory external to the first VM and the second VM, the shared memory to be populated with cache state information to permit common monitoring of the external cache.

3. The system of claim 1 wherein the cache infrastructure component comprises:

a plurality of regions, one region assigned to one additional component in the first VM and corresponding region assigned a corresponding additional component in the second VM.

4. The system of claim 1 wherein each cache infrastructure component comprises:

at least one eviction plugin.

5. The system of claim 1 wherein the cache infrastructure component comprises:

at least one storage plugin.

6. The system of claim 1 wherein the cache infrastructure component comprises:

a cache management library (CML).

7. The system of claim 1 wherein the cache infrastructure component comprises:

a cache region factory.

8. The system of claim 1 wherein the first VM is a Java VM (JVM).

9. A method comprising:

receiving a request from a first component in a first virtual machine (VM) to register for a region of cache;

storing an object in the cache responsive to a command of the first component; and

retrieving the object into a second VM responsive to a command from a corresponding component in the second VM.

10. The method of claim 9 further comprising:

applying an eviction policy when a threshold of cache usage is reached.

11. The method of claim 10 wherein applying comprises:

establishing an eviction policy on a region by region basis.

12. The method of claim 9 wherein storing comprises:

using the region as an access point to the cache.

13. The method of claim 9 further comprising:

populating shared memory with cache state information responsive to cache activity.

14. The method of claim 13 further comprising:

monitoring caching activity outside of a VM performing the activity.

15. A machine-accessible medium containing instructions that, when executed, cause a machine to:

receive a request from a first component in a first virtual machine (VM) to register for a region of cache;

store an object in the cache responsive to a command of the first component; and

retrieve the object into a second VM responsive to a command from a corresponding component in the second VM.

16. The machine accessible median of claim 15 further comprising instructions to cause the machine to:

populate shared memory with cache state information responsive to cache activity.

17. The machine accessible median of claim 16 further comprising instructions to cause the machine to:

monitor a state of the cache externally from either the first VM or the second VM.

18. The machine accessible median of claim 15 further comprising instructions to cause the machine to:

apply an eviction policy when a threshold of cache usage is reached.

19. The machine accessible median of claim 18 further comprising instructions to cause the machine to:

establish an eviction policy on a region by region basis.

20. An apparatus comprising:

means for accessing an external cache by a plurality of components within a virtual machine; and

means for monitoring the external cache remote from the virtual machine.

21. The apparatus of claim 20 wherein the means for accessing comprises:

means for storing content to the external cache; and

means for evicting content from the external cache.

22. The apparatus of claim 20 wherein the means for storing and the means for evicting comprise:

means for establishing storage policies and eviction policies on a component-by-component basis.