Messaging system and method of operation thereof

A messaging system comprising a plurality of messaging engines, each messaging engine comprising a processor and a communication interface for communicating with other messaging engines, at least one of the messaging engines arranged to receive a message, to create a list element for the message, the list element comprising expiry data and a reference to the message, to append the list element to an expiry list, to periodically delete list elements from the expiry list that correspond to consumed messages and to transfer list elements that correspond to unconsumed messages from the expiry list to a time sorted expiry index, and to traverse the expiry index deleting those messages that have expired.

A computer program product on a computer readable medium for controlling a data processing system, the computer program product comprising instructions for operating a messaging system comprising receiving a message, creating a list element for the message, the list element comprising expiry data and a reference to the message, appending the list element to an expiry list, periodically deleting list elements from the expiry list that correspond to consumed messages and transferring list elements that correspond to unconsumed messages from the expiry list to a time sorted expiry index, and traversing the expiry index deleting those messages that have expired.