Abstract: A system and method for messaging in which, when a connection to a queue manager (220) is established, the queue manager allocates a Connection Identifier from the same name space (300) as Message Identifiers and returns this information (400) to the user. The user can then use this Connection Identifier as a Correlation Identifier, safe in the knowledge that it will not clash with any system generated Message Identifier or Correlation Identifier. A secondary benefit to this allocation scheme is that if a shared reply queue suffers from a build-up of messages then the Correlation Identifier in those messages can be used to identify the application expected to receive those messages.

Abstract: In a publish/subscribe data processing broker network having a plurality of broker data processing apparatuses each of which has an input for receiving published messages directly from a publisher application and/or receiving subscription data from a subscriber application, a first broker data processing apparatus has: a unit for receiving a data message published on a first topic by a first publisher application; and a unit for forwarding the received published data message to a subscriber application which has requested, by entering subscription data, to receive a message on the first topic; wherein the first broker data processing apparatus sends a declaration to at least one other broker data processing apparatus of said plurality of broker data processing apparatuses declaring that the first broker data processing apparatus is the only broker data processing apparatus that is directly communicating with a publisher application that is publishing on the first topic.

Abstract: A publishing data processing method for use in a publish/subscribe data processing broker network having a plurality of broker data processing apparatuses each of which has an input for receiving published messages directly from a publisher application and/or receiving subscription data directly from a subscriber application, the method includes steps of: Publishing a message on a topic to a first broker data processing apparatus; and providing an indication as to whether the published data message is to be considered as local to the first broker apparatus. Also included are an analogous subscribing data processing method, an analogous broker data processing method, apparatuses and computer program products.

Abstract: In a publish/subscribe data processing broker network having a plurality of broker data processing apparatuses each of which has an input for receiving published messages directly from a publisher application and/or receiving subscription data from a subscriber application, a first broker apparatus has: a software unit for receiving via said input subscription data from a subscriber application; a software unit for providing an acknowledgement to said subscriber application to acknowledge that the subscription data has been received; a software unit for propagating said subscription data to a group of other broker apparatuses; a software unit for determining whether said means for propagating has propagated said subscription data to the group of other broker apparatuses; and a software unit for receiving via said input an indication from said subscriber application that said acknowledgement should not be sent to the subscriber application until the means for determining has determined that said means for prop