Persistence: Stores and Durables

Persistence is the potential to store a message between sending and receiving it.

The topics that follow present persistence, stores, and durables from an application developer’s perspective. In particular, these topics focus on the modifications to programs that enable durable subscribers and correct interaction with a persistence cluster.

For an intuitive introduction and terminology, see “Persistence: Stores and Durables” in TIBCO FTL Concepts.

For advisories associated with persistence, see "Stores and Durables" in TIBCO FTL Development.

For coordination between developers and administrators, see TIBCO FTL Durable Coordination Form.

  • Purposes of Persistence
    The persistence infrastructure of stores and durables can serve three purposes: delivery assurance, apportioning message streams, and last-value availability. These purposes correspond to three types of durables: standard durables, shared durables, and last-value durables.
  • Basic Definitions for Persistence
  • Durable Subscribers
    A durable subscriber is a subscriber object in an application process that maintains its identity even if the process exits and restarts. It can receive messages from a durable in a persistence store.
  • Acknowledgment of Message Delivery
    A durable subscriber can acknowledge consuming a message to its durable in either of two ways.
  • Message Delivery Behavior
  • Maximum Message Size
    When an endpoint is associated with a persistence store, limit the maximum size of messages to 10MB each. Messages that exceed the environment’s maximum message size could disrupt the quorum of persistence servers, and prevent them from reforming a quorum.
  • Delivery Count for Shared Durables
    When a persistence server delivers a message from a shared durable to a subscriber, it includes a delivery count, indicating the number of times the persistence server has already delivered the message to other subscribers. It is good practice for message callbacks in application programs to check this value as evidence for messages that cause unexpected behavior.
  • Programmer’s Checklist Addenda for Stores and Durables
    This topic provides a checklist for programmers using persistence stores and durables.