Distributed queuing

Distributed queuing combines features of Rendezvous certified messaging and fault-tolerance functionality to provide load balancing and fault-tolerant process redundancy in the TIBCO Active Enterprise environment. Specifically, the TIBCO Rendezvous Adapter can use distributed queues to implement one-of-n certified delivery in which there are n listeners defined in a distributed queue. For a description of distributed queue features and guidance in the selection of distributed queue configuration parameters, see the TIBCO Rendezvous Concepts documentation.

Each distributed queue member session has two distinct roles: as a listener member and as a potential scheduler. In the listener member role, queue member sessions listen for task messages and process inbound task messages as assigned by the scheduler. TIBCO Rendezvous fault tolerance software maintains one active scheduler in each queue. If the scheduler process terminates, another member assumes the role of scheduler. The queue member session in the scheduler role assigns inbound tasks to listener members in the queue.

The member sessions of a distributed queue share the same reusable correspondent name indicating that they are members of that queue. This correspondent name is specified with the XXXXDISTRIBUTEDQUEUECH3 adapter command (-DQ). Each member session of a distributed queue must listen for messages with the same subject. Even when multiple members listen, only one member processes the message for each inbound message (or task).

You can control distributed queue attributes by using the Distributed Queue adapter command (-DQ) and the Queue Options adapter command (-QO).

To implement multiple distributed queue listeners, create multiple instances of map components that contain the Distributed Queue adapter command (-DQ), specifying the same distributed queue name and the same subject name using the Subject Name adapter command (-SBN). The mapping functionality should be identical across the maps.

Distributed queues do not use ledger files and distributed queue member sessions automatically require old messages from certified senders.