Sun Java System Message Queue 4.3 Administration Guide

Connecting Brokers into a Conventional Cluster

There are two general methods of connecting brokers into a conventional cluster: from the command line (using the -cluster option) or by setting the imq.cluster.brokerlist property in the cluster configuration file.

Whichever method you use, each broker that you start attempts to connect to the other brokers in the cluster every five seconds; the connection will succeed once the master broker is started up (if one is configured). If a broker in the cluster starts before the master broker, it will remain in a suspended state, rejecting client connections, until the master broker starts; the suspended broker then will automatically become fully functional. It is therefore a good idea to start the master broker first and then the others, after the master broker has completed its startup.

When connecting brokers into a conventional cluster, you should be aware of the following issues:

ProcedureTo Connect Brokers Using a Cluster Configuration File

The method best suited for production systems is to use a cluster configuration file to specify the configuration of the cluster:

  1. Create a cluster configuration file that uses the imq.cluster.brokerlist property to specify the list of brokers to be connected.

    If you are using a master broker, identify it with the imq.cluster.masterbroker property in the configuration file.

  2. For each broker in the cluster, set the imq.cluster.url property in the broker’s instance configuration file to point to the cluster configuration file.

  3. Use the imqbrokerd command to start each broker.

    If there is a master broker, start it first, then the others after it has completed its startup.

ProcedureTo Connect Brokers from the Command Line

  1. If you are using a master broker, start it with the imqbrokerd command, using the -cluster option to specify the complete list of brokers to be included in the cluster.

    For example, the following command starts the broker as part of a cluster consisting of the brokers running at the default port (7676) on host1, at port 5000 on host2, and at port 9876 on the default host (localhost):

       imqbrokerd  -cluster host1,host2:5000,:9876
  2. Once the master broker (if any) is running, start each of the other brokers in the cluster with the imqbrokerd command, using the same list of brokers with the -cluster option that you used for the master broker.

    The value specified for the -cluster option must be the same for all brokers in the cluster.

ProcedureTo Establish Secure Connections Between Brokers

If you want secure, encrypted message delivery between brokers in a cluster, configure the cluster connection service to use an SSL-based transport protocol:

  1. For each broker in the cluster, set up SSL-based connection services, as described in Message Encryption.

  2. Set each broker’s imq.cluster.transport property to ssl, either in the cluster configuration file or individually for each broker.