Use Cases for Direct Publishers and Subscribers

Direct publishers and subscribers are appropriate only in very specialized use cases in which a few nanoseconds of latency can make a critical difference.

Direct publishers and subscribers are less flexible than regular TIBCO FTL communications. Direct publishers omit several features in exchange for greater speed and lower latency:
  • The implementation has fewer protections against incorrect use of the API calls. For example, it does not check arguments nor data types. The implementation does not protect against writing beyond buffer boundaries.
  • Data is in buffers, rather than in messages with typed fields.
  • Event queues are not available.
  • Content matchers are not available.
  • Persistence is not available.
  • C is the only supported programming language.

Direct shared memory transports support only one direct publisher per bus. This restriction precludes the request/reply pattern, which requires two-way communication. Nonetheless, you could use a separate bus for replies.