Abstract: The present invention provides methods, apparatus and computer programs for event-based control of subscription matching in a publish/subscribe communications environment. Activation and/or deactivation events are associated with subscriptions at a publish/subscribe broker and are used to control when a subscription is active. The broker is responsive to temporally-unpredictable events, such as receipt of a published message on a predefined activation topic, to activate subscription matching for messages that are subsequently received or which have been received earlier and retained at the broker. Conventional subscription matching can be avoided for a registered subscription while that subscription is inactive, and subscribers are not required to explicitly and repeatedly subscribe and unsubscribe.

Abstract: Provided are a method, apparatus and a computer program for managing message queues. Message streaming is enabled in a transactional messaging system that supports priority ordering of messages, without the need for complex locking mechanisms. Any messages which are transferred from a message queue to a message consumer after the message consumer initiates commit processing are replaced on the message queue at an appropriate position ahead of other messages. As part of commit processing, the consumer sends back to the manager of the message queue an identification of messages delivered to it before the commit, and this list of messages is extracted and compared with a message log to identify undelivered messages. Successfully delivered and committed messages can be committed by the queue manager, and undelivered messages can be replaced on the queue. A special high priority is assigned to the replaced messages to place them ahead of other messages.

Abstract: Provided are a method, apparatus and a computer program for managing message queues. Message streaming is enabled in a transactional messaging system that supports priority ordering of messages, without the need for complex locking mechanisms. Any messages which are transferred from a message queue to a message consumer after the message consumer initiates commit processing are replaced on the message queue at an appropriate position ahead of other messages. As part of commit processing, the consumer sends back to the manager of the message queue an identification of messages delivered to it before the commit, and this list of messages is extracted and compared with a message log to identify undelivered messages. Successfully delivered and committed messages can be committed by the queue manager, and undelivered messages can be replaced on the queue. A special high priority is assigned to the replaced messages to place them ahead of other messages.

Abstract: The present invention provides methods, apparatus and computer programs for event-based control of subscription matching in a publish/subscribe communications environment. Activation and/or deactivation events are associated with subscriptions at a publish/subscribe broker and are used to control when a subscription is active. The broker is responsive to temporally-unpredictable events, such as receipt of a published message on a predefined activation topic, to activate subscription matching for messages that are subsequently received or which have been received earlier and retained at the broker. Conventional subscription matching can be avoided for a registered subscription while that subscription is inactive, and subscribers are not required to explicitly and repeatedly subscribe and unsubscribe.