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: Messages in a publish/subscribe system can be processed after they leave the original publisher and before they are delivered to an ultimate subscriber. Each published message has an associated topic string and a PubLevel value initially assigned by the original publisher. Subscribers are assigned different SubLevel values. These subscribers register their subscriptions with a broker. When a published message having the appropriate topic string is received, the broker performs a subscriber selection process using the message topic string, the current message PubLevel value and the assigned SubLevel values of subscribers registered for the topic string. When a subscriber is selected, the broker changes the message PubLevel value and transmits the message only to the selected subscriber. The subscriber may be an intercepting subscriber that processes the published message and then re-publishes it back to the broker.

Abstract: Messages in a publish/subscribe system can be processed after they leave the original publisher and before they are delivered to an ultimate subscriber. Each published message has an associated topic string and a PubLevel value initially assigned by the original publisher. Subscribers are assigned different SubLevel values. These subscribers register their subscriptions with a broker. When a published message having the appropriate topic string is received, the broker performs a subscriber selection process using the message topic string, the current message PubLevel value and the assigned SubLevel values of subscribers registered for the topic string. When a subscriber is selected, the broker changes the message PubLevel value and transmits the message only to the selected subscriber. The subscriber may be an intercepting subscriber that processes the published message and then re-publishes it back to the broker.