Exactly once JMS communication

• US 20060235952A1
• Filed: 06/13/2006
• Published: 10/19/2006
• 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 7,409,436 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• 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:

receiving, at a host server selected from a plurality of servers forming a cluster in the network using a distributed consensus algorithm, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network;

receiving, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

providing at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS.

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 servers.

3. 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.

4. The method of claim 1, further comprising:

ensuring the existence of a JMS object in a cluster by;

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

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

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

5. The method of claim 1, further comprising:

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

contacting each remaining 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.

6. A computer-readable medium carrying one or more sequences of instructions for managing objects on a network, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

receiving, at a host server selected from a plurality of servers forming a cluster in the network using a distributed consensus algorithm, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network;

receiving, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

providing at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS.

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

computer code for receiving, at a host server selected from a plurality of servers forming a cluster in the network using a distributed consensus algorithm, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network;

computer code for receiving, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message;

computer code for receiving, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

computer code for providing at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS; and

a machine-readable medium for containing the computer codes.

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

means for receiving, at a host server selected from a plurality of servers forming a cluster in the network using a distributed consensus algorithm, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network;

means for receiving, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

means for providing at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS.

9. A computer system comprising:

a processor;

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

receive, at a host server selected from a plurality of servers forming a cluster in the network using a distributed consensus algorithm, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network;

receive, at the JMS message store on the host server, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

provide at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS.

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

receiving, at a JMS message store on a host server selected from a plurality of servers forming a cluster in the network using a Paxos algorithm, at least one indication from at least one remaining server in the cluster that the remaining server needs to send a message; and

providing at least one message from the message store to the remaining server, thereby allowing the remaining server in the cluster to be able to use JMS.

11. A method according to claim 10, further comprising the step of:

receiving at the host server, an assignment of a JMS object, the JMS object comprising a JMS message store to provide a sole access point and a message queue for JMS over the network.

12. A method according to claim 10, further comprising the step of:

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

13. A method according to claim 10, further comprising:

selecting the host server from among the plurality of servers in a software cluster using a Paxos algorithm by multicasting rounds of information to the other servers in the network.