Abstract: A messaging system having a cluster of receiving applications for handling received messages, and a cluster of messaging engines for receiving messages from one or more message sources and forwarding the received messages to one of the receiving applications is provided. Each messaging engine is operable to transmit load balancing information, the load balancing information comprising an indication of the current loading on the messaging engine. The receiving applications are instructed to establish a connection to receive messages from a particular messaging engine within the cluster based on the load balancing information. Accordingly, applications are able to receive messages in such a way that the messages do not build up unprocessed on a particular messaging engine for too long, and such that messages are routed to messaging engines where messages are being consumed, and so that the receiving applications receive messages from every messaging engine where messages are arriving.

Abstract: Topics are linked in a publish/subscribe messaging environment. A first topic is linked to at least a second topic, and a message on the first topic is published to subscribers to the first topic. In the same transaction, any reference to the topics linked to the first topic are published in the message to subscribers of the topics linked to the first topic. A tree of topics is defined with topic nodes for each topic. A topic string is provided in a path through the tree of topics to a topic node, wherein the first topic and the at least a second topic have no commonality of topic string.