Exactly once JMS communication

• US 20030065708A1
• Filed: 09/04/2002
• Published: 04/03/2003
• Est. Priority Date: 09/06/2001
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: BEA Systems Incorporated (Oracle Corporation)
• Inventors: Jacobs, Dean Bernard, Halpern, Eric M.
• Granted Patent: US 7,113,980 B2
• Time in Patent Office: Days
• US Class Current: 709/201
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A system for managing a JMS message store in a clustered network includes an object acting as a message store for Java Message Service (JMS). A lead server is selected from several clustered servers. The lead server uses a distributed consensus algorithm to select a host server, utilizing multicast messaging while executing rounds of the algorithm. The selected host server hosts the JMS message store, providing sole access to JMS. The other servers are notified of the new host by multicast messaging. All servers in the cluster can use JMS, but they must send messages to the message store on the host and pick up any messages from the message store.

Claims

1. A method for hosting Java Messenger Service (JMS) on a network, comprising:

selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

assigning a JMS object the host server, the JMS object comprising a JMS message store providing the sole access point and message queue for JMS over the network; and

notifying the network servers that the host server is hosting the sole JMS message store.

2. A method according to claim 1, further comprising the step of:

checking the JMS message store for messages intended for one of the plurality of network servers.

3. A method according to claim 1, further comprising the step of:

sending a JMS message from a network server to the JMS message store on the host server.

4. A method according to claim 1, further comprising the step of:

sending messages in the JMS message store on the host server to a JMS component.

18. A system according to claim 1, wherein said distributed consensus algorithm is a Paxos algorithm.

5. A method for ensuring the existence of a JMS object in a cluster, comprising:

providing access to a JMS object using a host server in a plurality of servers, the JMS object comprising a JMS message store providing the sole access point and message queue for JMS over the network;

selecting a new host server from among the plurality of servers using a distributed consensus algorithm if the host server is unable to provide access to the JMS object;

pulling information to the new host server needed to provide access to the JMS object; and

notifying other servers in said plurality of servers that a new host server is providing access to the JMS object.

6. A method for assigning a JMS object to a server in a cluster, comprising:

selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

contacting each server in the cluster to determine whether the selected host is acceptable to that server; and

multicasting a notification to other servers in the cluster to commit the selection of a new host server if all servers in the cluster agree that the selected host is acceptable.

7. A computer-readable medium, comprising:

means for selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

means for assigning a JMS object to the host server, the host server assigned to provide sole access to JMS; and

means for notifying other network servers that the host server provides sole access to JMS.

8. A computer program product for execution by a server computer for managing objects on a network, comprising:

computer code for selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

computer code for assigning a JMS object to the host server, the host server assigned to provide sole access to JMS; and

computer code for notifying other network servers that the host server provides sole access to JMS.

9. A system for distributing objects in a cluster, comprising:

means for selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

means for assigning a JMS object to the host server, the host server assigned to provide sole access to JMS; and

means for notifying other network servers that the host server provides sole access to JMS.

10. A computer system comprising:

a processor;

object code executed by said processor, said object code configured to;

select a host server from among a plurality of network servers using a distributed consensus algorithm;

assign a JMS object to the host server, the host server assigned to provide sole access to JMS

notify other network servers that the host server provides sole access to JMS.

11. A method for managing a JMS message store on a network, comprising:

selecting a host server from among a plurality of network servers in a software cluster using a Paxos algorithm; and

assigning a JMS message store to the host server, the JMS message store existing only on the host server.

12. A method according to claim 11, further comprising the step of:

notifying other network servers that the host server is hosting a JMS message store.

13. A method according to claim 11, further comprising the step of:

multicasting the identification of the new host server to the other network servers.

14. A method according to claim 11, wherein said step of selecting a host server from among a plurality of network servers in a software cluster using a Paxos algorithm comprises multicasting rounds of information to the other network servers.

15. A system for managing a JMS object on a network, comprising:

a plurality of network servers; and

a lead server in said plurality of network servers, the lead server containing a distributed consensus algorithm for selecting a host server from said plurality of network servers, the host server containing a JMS object such that any of said plurality of network servers needing to access JMS must access the JMS object on the host server.

16. A system according to claim 15, wherein said network servers are selected from the group consisting of hardware cluster servers and software cluster servers.

17. A system according to claim 15, wherein said distributed consensus algorithm comprises rounds of messages between said lead server and said plurality of servers, the rounds continuing until a majority of said plurality of network servers agrees on the host server.

19. A system for managing JMS on a network, comprising:

a JMS component;

a plurality of servers in communication with the JMS component;

a lead server in said plurality of servers, the lead server containing a distributed consensus algorithm for selecting a host server from said plurality of servers; and

a host server in said plurality of servers, said host server containing a JMS message store, said host server adapted to provide access to the JMS component to any of said plurality of servers.

20. A system according to claim 19, wherein said plurality of servers comprise a cluster.

21. A system for managing JMS on a network, comprising:

a JMS component;

a plurality of servers in communication with the JMS component;

a hardware cluster containing hardware cluster servers located in said plurality of servers, said hardware cluster containing an algorithm for selecting a lead server from among said hardware cluster servers;

a lead server in said hardware cluster servers, the lead server containing a distributed consensus algorithm for selecting a host server from said plurality of servers; and

a host server in said plurality of servers, said host server containing a JMS message store, said host server adapted to provide access to JMS to any of said plurality of servers.

22. A system according to claim 21, wherein said host server is in said hardware cluster.

23. A framework for managing JMS on a network, comprising:

a plurality of servers, each server capable of hosting a JMS message store;

a distributed consensus algorithm for selecting a host server from among said plurality of servers, the host server to host a JMS message store; and

a distribution system for notifying servers on the network that the host computer is hosting the JMS message store.

24. A method for leasing a JMS object to a server on a network, comprising:

selecting a host server from among a plurality of network servers using a distributed consensus algorithm;

assigning a JMS object to the host server, the host server assigned to provide sole access to JMS for a specific period of time; and

notifying other network servers that the host server is hosting the JMS object.

25. A method according to claim 24, further comprising the step of:

assigning the JMS object to the host server for another period of time once the specific period of time expires.

26. A method according to claim 24, further comprising the step of:

assigning the JMS object to a new host server for another specific period of time once the specific period of time expires on the host server.

27. A method for leasing a JMS object to a server on a network, comprising:

selecting a lead server from among a plurality of hardware cluster servers in a hardware cluster;

selecting a host server from among a plurality of network servers using a distributed consensus algorithm on said lead server;

assigning a JMS object to the host server, the host server assigned to provide sole access to JMS for a specific period of time; and

notifying other network servers that the host server is hosting the JMS object.

28. A method for assigning ownership of an object on a network, comprising:

selecting a lead server from among a plurality of hardware cluster servers in a hardware cluster;

selecting a host server from among a plurality of network servers using a distributed consensus algorithm on said lead server;

assigning a JMS object to the host server, the host server assigned to provide sole access to JMS; and

notifying other network servers that the host server is hosting the JMS object.