A Blazix JMS client is given one or more JMS server addresses. However, the actual service will be provided by any one of the JMS servers in the JMS cluster. This is automatically determined based upon the servers' current load.
The JMS client should be given at least two server addresses, so if one fails, the JMS client will have at least one point of entry into the cluster. Note that once the JMS client has connected, all the servers it originally knew about may crash, and it will continue to be able to send or get messages as long as at least one JMS server in the cluster is operational.