Patent ID: 8122118

Claim:
A method of communication in a publish/subscribe environment in which publisher programs send messages to subscriber programs via one or more message brokering systems, the method comprising the following steps: responsive to receipt of a published message at a message broker, referring to characteristics of the received message and subscriber-specified quality of service requirements to determine an appropriate quality of service for onward transmission of the message; selecting a communication protocol in accordance with the determined quality of service; and transmitting the message using the selected communication protocol, wherein the message broker determines said appropriate quality of service by determining which subset of subscribers are currently connected to the message brokering system and referring to the subscriber-specified quality of service requirements for only the currently connected subset of subscribers, and the subscriber-specified quality of service requirements include an indication of whether transactional message delivery is required, and wherein the protocol selecting step comprises selecting a transactional communication protocol for messages which match subscriptions which include said transactional message delivery requirement, for only the currently connected subset of subscribers.