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This topic provides a summary of information about using WebSphere Application Server horizontal cloning with MQSeries server clustering support. It describes a scenario that shows how the extended messaging service can be configured to take advantage of MQSeries server clustering and provides some information about how to resolve potential runtime failures in the clustering scenario. The information in this topic is based on the scenario shown in [WebSphere Application Server horizontal cloning with MQSeries clustered queues].
For a WebSphere application server configured to use the extended messaging service, each JMS listener is used to retrieve messages from destinations defined to the server. In the following information the listener configurations are the same for each WebSphere application server. Each application server host contains a WebSphere application server and an MQSeries server. If a host is only used to distribute messages, it only contains an MQSeries server. There can be many servers defined in the configuration, although for simplicity the information in this topic is based on a scenario containing only three servers as shown in [WebSphere Application Server horizontal cloning with MQSeries clustered queues].
WebSphere Application Server horizontal
cloning with MQSeries clustered queues. This figure shows two WebSphere Application Server hosts, with horizontal clustering, and a messaging host used to distribute messages for MQSeries server clustering. For more information, see the text that accompanies this figure.
The scenario shown in [WebSphere Application Server horizontal cloning with MQSeries clustered queues] comprises the following three hosts:
This host does not have a WebSphere application server defined. All message retrieval processing is performed by the other two application servers on hosts S1 and S2.
Recovery scenarios
There are several failure scenarios that could occur with the clustering configuration; for example:
In this scenario the failure of any single WebSphere application server results in the messages for the specified destination remaining on the queue, until the server is restarted. There is no automatic fail over, and messages are saved on the local queue. A side effect of this failure is for the message queue (Q1) to fill up, as no JMS listener is retrieving messages. The MQSeries cluster queue continues to receive messages until the queue manager stops receiving messages.
There are two different failures to consider:
There are two different failures to consider:
Related concepts... | |
Parent: An overview of the extended messaging service | |