Session monitoring using shared memory

• US 20060143290A1
• 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: Werner, Randolf, Dostert, Jan, Kilian, Frank, Stanev, Georgi, Fleischer, Christian
• Granted Patent: US 7,523,196 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms

Abstract

A system and method to monitor client sessions within a Java virtual machine. Client sessions are established within an application server instance to store session context data for each of the client sessions during the client sessions. At least two Java virtual machines are operated within the application server instance to service client requests received from clients associated with each of the client sessions. Status information about each of the client sessions is reported into shared memory external to the Java virtual machines to monitor each of the client sessions during operation of the Java virtual machines.

Claims

1. A method, comprising:

establishing client sessions within an application server instance;

storing session context data for each of the client sessions during the client sessions;

operating at least one Java virtual machine (“

JVM”

) within the application server instance to service client requests received from clients associated with each of the client sessions; and

reporting status information about each of the client sessions into shared memory external to the at least one JVM to monitor each of the client sessions during operation of the at least one JVM.

2. The method of claim 1, wherein establishing the client sessions comprises establishing connections between the clients and the JVMs to receive the client requests and to transmit corresponding server responses.

3. The method of claim 2, wherein operating the JVMs to service the client requests comprises:

executing Java programs on the JVMs;

processing the client requests based on logic of the Java programs to generate results, wherein the session context data includes Java objects created during processing the client requests; and

generating the server responses to the client requests based at least in part on the results.

4. The method of claim 1, wherein reporting the status information about each of the client sessions into the shared memory comprises:

registering a reporting slot within the shared memory for each of the client sessions; and

reporting the status information about each of the client sessions into a corresponding one of the reporting slots.

5. The method of claim 4, wherein reporting the status information about each of the client sessions into the corresponding one of the reporting slots comprises reporting at least a portion of the status information about each of the client sessions into the corresponding one of the reporting slots in response to at least one of a commencement and a completion of a request/response cycle.

6. The method of claim 1, wherein the status information corresponding to one of the client sessions includes at least one of a size of the one of the client sessions, a timeout period, a count of the client requests received for the one of the client sessions, a creation timestamp, a last update timestamp, a name of the one of the clients corresponding to the one of the client sessions, and a session ID for the one of the client sessions.

7. The method of claim 1, further comprising:

saving the session context data corresponding to at least a portion of the client sessions to a backup store between request/response cycles; and

reporting the status information including a designation of the backup store into the shared memory.

8. The method of claim 7, further comprising:

terminating one of the client sessions when the one of the client sessions no longer persists;

cleaning the backup store of session context data corresponding to the terminated client session; and

cleaning the shared memory of the status information corresponding to the terminated client session.

9. The method of claim 7, wherein the designation of the backup store includes a designation of one of:

the client session not persisted, a file system, a database, the shared memory, and a shared closure.

10. The method of claim 1, further comprising:

retrieving the status information about the client sessions from the shared memory; and

transmitting the status information to a monitoring console to display the status information in a user readable format.

11. A machine-accessible medium that provides instructions that, if executed by a machine, will cause the machine to perform operations comprising:

receiving client requests at an application server (“

AS”

) instance;

associating the client requests with a client session and a Java virtual machine (“

JVM”

) from among a plurality of client sessions and a plurality of JVMs maintained within the AS instance;

responding to the client requests with server responses; and

reporting session status information about the client session into shared memory, the shared memory shared by the plurality of JVMs to monitor the plurality of client sessions during operation of the plurality of JVMs.

12. The machine-accessible medium of claim 11, wherein reporting the session status information about the client session into the shared memory comprises:

registering reporting slots within the shared memory for each of the plurality of client sessions including the client session; and

reporting the status information about the client session into a corresponding one of the reporting slots.

13. The machine-accessible medium of claim 11, wherein the status information corresponding to the client session includes at least one of a size of the client session, a timeout period for the client session, a count of the client requests received for the client session, a creation timestamp of the client session, a last update timestamp for the client session, a name of a client generating the client requests, and a session ID for the client session.

14. The machine-accessible medium of claim 11, further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

saving session context data for the client session to a backup store; and

reporting the session status information including a designation of the backup store into the shared memory.

15. The machine-accessible medium of claim 14, further providing instructions that, if executed by the machine, will cause the machine to perform further operations, comprising:

terminating the client session when the client session is determined no longer to persist;

cleaning the backup store of the session context data; and

cleaning the shared memory of the session status information for the client session.

16. A system, comprising:

a server node to execute an application server (“

AS”

) instance, the AS instance including logic executable by a processor of the server node to;

receive client requests at the AS instance from a client;

associate the client requests with a client session and a Java virtual machine (“

JVM”

) from among a plurality of client sessions and a plurality of JVMs maintained within the AS instance;

respond to the client requests with server responses; and

report session status information about the client session into shared memory, the shared memory shared by the plurality of JVMs to monitor the plurality of client sessions during operation of the plurality of JVMs.

17. The system of claim 16, wherein reporting the session status information into the shared memory comprises reporting the session status information into the shared memory in response to at least one of a commencement and a completion of a request/response cycle.

18. The system of claim 17, wherein reporting the session status information about the client session into the shared memory comprises:

registering reporting slots within the shared memory for each of the plurality of client sessions including the client session; and

reporting the status information about the client session into a corresponding one of the reporting slots.

19. The system of claim 16, wherein the AS instance further includes logic executable by the processor of the server node to:

save session context data for the client session to a backup store; and

report the session status information, including a designation of the backup store, into the shared memory.

20. The system of claim 16, further comprising a client node to execute a monitoring console, the monitoring console including logic executable by a processor of the client node to:

send a status query to the server node;

receive the session status information from the server node; and

display the session status information in a user readable format.