Transparent migration of stateless sessions across servers

• US 20050038828A1
• Filed: 08/12/2004
• Published: 02/17/2005
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Gollapudi, Sreenivas, Kaluskar, Sanjay
• Granted Patent: US 7,747,754 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: H04L 67/148 Migration or transfer of sessions

Abstract

Techniques allow a client to be migrated from a session that has been established for a client on a server to another session on another server in a way that is a transparent to the application for which the initial session was established. The sessions are migrated under conditions in which a copy of session state of the session to migrate from the source node does not have to be captured and restored to a destination session.

Claims

1. A method for managing sessions on a multi-node system, the method comprising the steps of:

receiving a request to establish a certain session for a client of the multi-node system;

establishing as the certain session a first session on a first node of the multi-node system;

receiving first data from the client that indicates one or more criteria for transferring sessions between the first node and a second node of said multi-system;

based on said one or more criteria, determining to transfer the first session to the second node of the multi-node system; and

in response to determining to transfer the first session, establishing a second session on the second node as the certain session for the client on the multi-node system.

2. The method of claim 1, wherein the one or more criteria are based on whether the first session is stateless.

3. The method of claim 1, wherein the one or more criteria are based on whether a transaction associated with the first session has terminated.

4. The method of claim 1, wherein the one or more criteria are based on whether client call associated with the first session has been completed.

5. The method of claim 1, wherein the one or more criteria indicates whether a subsequent application call made after a first application call depends on first session state generated for the first application call.

6. The method of claim 5, wherein said subsequent application call depends on said first session state.

7. The method of claim 1, wherein

a server hosts said client and a plurality of other sessions;

said server maintains a pool of sessions on said first node, said pool including said first session; and

said server assigns and unassigns said first session to said plurality of other session.

8. The method of claim 7, wherein said server is an application server.

9. A method for managing sessions on a multi-node system, the method comprising the steps of:

receiving a request to establish a certain session for a client of the multi-node system;

establishing as the certain session a first session on a first node of the multi-node system;

receiving from the client first data that identifies said first session as a session that can be migrated between the first node and a second node without having to capture the first session'"'"'s state;

based on the first data, determining to migrate the first session to the second node;

in response to determining to transfer the first session to the second node; and

establishing a second session on the second node as the certain session for the client on the multi-node system.

10. The method of claim 9, wherein said client transmits said first data in response to determining that a subsequent application call made after a first application call does not depend on first session state generated for the first application call.

11. The method of claim 9, the steps further including:

a server hosting said client and a plurality of other sessions;

said server maintaining a pool of sessions on said first node, said pool including said first session;

said server assigning said first session to a particular session of said other sessions; and

wherein said server assigning said first session causes said server to transmit said first data.