Abstract: In managing the backlog of undelivered publications for durable subscriptions, a maximum quantity of publications stored in connection with a durable subscription to publications of a particular topic can be established on behalf of a particular subscribing end user. A new publication published for the particular topic subscribed to by the end user can be received and it can be determined if storing the new publication in connection with the durable subscription causes a quantity of publications stored in connection with the durable subscription to exceed the maximum quantity. The new publication can be stored in connection with the durable subscription; however, the oldest publication stored in connection with the durable subscription can be removed when it is determined that storing the new publication in connection with the durable subscription causes a quantity of publications stored in connection with the durable subscription to exceed the maximum quantity.

Abstract: A message broker data processing apparatus comprising: a unit for receiving published messages on a topic from a plurality of publisher applications; a unit for processing the received messages; and a unit for distributing the processed messages to a subscriber application; wherein the unit for receiving includes a plurality of publication point data processing nodes, each of which receives published messages on the topic from a publisher application.

Abstract: A message broker data processing apparatus has a unit for receiving published messages on a topic from a publisher application; a unit for processing the received messages; and a unit for distributing the processed messages to subscriber applications; wherein the unit for distributing includes a plurality of subscription point data processing nodes, a first subscription point data processing node distributes messages to a subscriber application which has previously registered a subscription request identifying the first subscription point data processing node with the broker apparatus.

Abstract: A method for updating a first version of installed application files to a second version is disclosed. The method comprises the steps of: responsive to receiving a delta file defining the changes between a file in the first version and a corresponding file in the second version, transforming said first version of the file into a first transformed image comprising a series of records. The changes contained in the delta file are then applied to selected records of the first transformed image to generate a transformed image of the second version. The transformation on the transformed image of said second version is then reversed to generate the second version of said file on said client computer.