Broker Clusters

The following items relate to the use of broker clusters.

• Only fully-connected broker clusters are supported in this release. This means that every broker in a cluster must communicate directly with every other broker in the cluster. If you are connecting brokers using the imqbrokerd -cluster command line argument, be careful to ensure that all brokers in the cluster are included.

• A client connected to a broker that is part of a cluster cannot currently use QueueBrowser to browse queues that are located on remote brokers in that cluster. The client can only browse the contents of queues that are located on the broker to which it is directly connected. The client may still send messages to any queue or consume messages from any queue on any broker in the cluster; the limitation only affects browsing.

• If a master broker is not used in a broker cluster, persistent information stored by a broker being added to the cluster is not propagated to other brokers in the cluster.

• Connection is dropped for a broker in a cluster (Bug ID 6377527).

  One reason this can happen is that the broker address (whose connection is dropped) is resolved to be the loopback IP address (127.0.0.1).

  Workaround Make sure that the broker address does not resolve to the loopback IP address.

• In a broker cluster, a broker will queue messages to a remote connection which has not been started (Bug ID 4951010).

  WorkaroundThe messages will be received by the consumer once the connection is started. The messages will be redelivered to another consumer if the consumer’s connection is closed.