System and method for managing memory of Java session objects

• US 20060143609A1
• 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: Stanev, Georgi
• Granted Patent: US 8,015,561 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 11/1484 involving virtual machines

Abstract

A method for managing a session with a client is described in which the method receives from the client a request for the session. The session is handled with a first virtual machine. The method places the session state information for the session into an object located in the first virtual machine'"'"'s local memory. The method writes into a shared memory an object that contains the session state information. In response to a failure that renders the first virtual machine unable to handle the session, the method reads the object in the shared memory from the shared memory and places it into a second virtual machine'"'"'s local memory. Lastly, the method receives from the client another request for the session, and handles the another request with the second virtual machine and the session state information.

Claims

1. A method for managing a session with a client, comprising:

receiving from said client a request for said session, said session handled with a first virtual machine;

placing session state information for said session into an object located in said first virtual machine'"'"'s local memory;

writing into a shared memory an object that contains said session state information;

in response to a failure that renders said first virtual machine unable to handle said session;

reading said object in said shared memory from said shared memory and placing it into a second virtual machine'"'"'s local memory;

receiving from said client another request for said session; and

handling said another request with said second virtual machine and said session state information.

2. The method of claim 1 wherein said first and second virtual machines are both Java virtual machines.

3. The method of claim 2 wherein said first virtual machine interprets code for a first Java container and said second virtual machine interprets code for a second Java container.

4. The method of claim 1 wherein said method further comprises placing said object in said first virtual machine'"'"'s local memory into a deactivated state before said writing;

5. The method of claim 4 wherein said method further comprises deleting said object in said first virtual machine'"'"'s local memory while it is in said deactivated state.

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

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

receiving from said client a request for said session, said session handled with a first virtual machine;

placing session state information for said session into an object located in said first virtual machine'"'"'s local memory;

writing into a shared memory an object that contains said session state information;

in response to a failure that renders said first virtual machine unable to handle said session;

reading said object in said shared memory from said shared memory and placing it into a second virtual machine'"'"'s local memory;

receiving from said client another request for said session; and

handling said another request with said second virtual machine and said session state information.

8. The article of manufacture of claim 7 wherein said first and second virtual machines are both Java virtual machines.

9. The article of manufacture of claim 8 wherein said first virtual machine interprets code for a first Java container and said second virtual machine interprets code for a second Java container.

10. The article of manufacture of claim 7 wherein said method further comprises placing said object in said first virtual machine'"'"'s local memory into a deactivated state before said writing;

11. The article of manufacture of claim 10 wherein said method further comprises deleting said object in said first virtual machine'"'"'s local memory while it is in said deactivated state.

12. The article of manufacture of claim 7 wherein said object is a member of a shared closure.

13. A method for managing a session with a client, comprising:

receiving from said client a request for said session, said session handled with a first virtual machine;

placing session state information for said session into an object located in said first virtual machine'"'"'s local memory;

writing into a shared memory an object that contains said session state information;

creating a reference from said object in said shared memory to said object in said first virtual machine'"'"'s local memory;

in response to a failure that renders said first virtual machine unable to handle said session;

reading said object in said shared memory from said shared memory and placing it into a second virtual machine'"'"'s local memory;

receiving from said client another request for said session; and

handling said another request with said second virtual machine and said session state information.

14. The method of claim 13 wherein said first and second virtual machines are both Java virtual machines.

15. The method of claim 13 wherein said object is a member of a shared closure.

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

receiving from said client a request for said session, said session handled with a first virtual machine;

placing session state information for said session into an object located in said first virtual machine'"'"'s local memory;

writing into a shared memory an object that contains said session state information;

creating a reference from said object in said shared memory to said object in said first virtual machine'"'"'s local memory;

in response to a failure that renders said first virtual machine unable to handle said session;

reading said object in said shared memory from said shared memory and placing it into a second virtual machine'"'"'s local memory;

receiving from said client another request for said session; and

handling said another request with said second virtual machine and said session state information.

17. The article of manufacture of claim 16 wherein said first and second virtual machines are both Java virtual machines.

18. The article of manufacture of claim 16 wherein said object is a member of a shared closure.