The Cluster Configuration File

Like all broker properties, cluster configuration properties can be set individually for each broker in a cluster, either in its instance configuration file (config.properties) or by using the -D option on the command line when you start the broker. However, except where noted in this chapter, each cluster configuration property must be set to the same value for each broker in a cluster. must be the same

For example, to specify the transport protocol for the cluster connection service, you can include the following property in the instance configuration file for each broker in the cluster:

imq.cluster.transport=ssl

Notice, however, that if you need to change the value of this property, you must change its value in the instance configuration file for every broker in the cluster.

For consistency and ease of maintenance, it is generally more convenient to collect all of the common cluster configuration properties into a central cluster configuration file that all of the individual brokers in a cluster reference. Using a cluster configuration file prevents the settings from getting out of synch and ensures that all brokers in a cluster use the same, consistent configuration information.

When using a cluster configuration file, each broker’s instance configuration file must point to the location of the cluster configuration file by setting the imq.cluster.url property. For example,

imq.cluster.url=file:/home/cluster.properties