Session monitoring using shared memory

• US 7,523,196 B2
• Filed: 12/28/2004
• Issued: 04/21/2009
• 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
• Primary Examiner(s): Hu; Jinsong
• Application Number:
  US11/024,391
• Publication Number:
  US 20060143290A1
• Time in Patent Office: 1,575 Days
• Field of Search: 709/220, 709/223, 709/224, 709/245, 715/734, 715/736
• 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 implemented in a network for monitoring client sessions, comprising:

establishing client sessions within an application server instance, wherein each of the client sessions is established by a respective worker node in a plurality of worker nodes, each worker node providing a runtime environment for a respective Java virtual machine (“

JVM”

) of a plurality of JVMs in the application server instance;

storing by each of the plurality of JVMs session context data for a respective one of the client sessions during the client sessions;

operating each of the plurality of JVMs to service a respective client request received from a client associated with one of the client sessions; and

each of the plurality of JVMs reporting status information about one of the client sessions into a shared memory external to the plurality of JVMs, the reporting to monitor each of the client sessions during operation of the JVMs.

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 JYMs 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 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-readable storage medium having stored executable instructions to cause a machine to perform operations comprising:

receiving client requests at an application server (“

AS”

) instance;

associating each of the client requests with a respective 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, wherein each of the plurality of client sessions is established by a respective worker node in a plurality of worker nodes within the AS instance, each worker node providing a runtime environment for a respective one of the plurality of JVMs;

responding to each of the client requests with a respective response of an associated JVM; and

each of the JVMs reporting session status information about a respective 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-readable storage medium of claim 11, wherein each of the JYMs reporting session status information into the shared memory comprises:

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

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

13. The machine-readable storage medium of claim 11, wherein the status information about one of the plurality of client sessions 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-readable storage medium of claim 11, the operations further comprising:

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

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

15. The machine-readable storage medium of claim 14 the operations further comprising:

terminating a 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 terminated client session.

16. A system to implement a monitoring of client sessions in a network, the system comprising:

a server node including a processor 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 each of the client requests with a respective 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, wherein each of the plurality of client sessions is established by a respective worker node in a plurality of worker nodes, each worker node providing a runtime environment for a respective one of the plurality of JVMs;

respond to each of the client requests with a respective response of an associated JVM; and

report session status information from each of the JVMs about a respective 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 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 each of the client sessions 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 a 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.