Short note: TIB/Rendezvous

TIB/Rendezvous is a message-oriented middleware product from TIBCO for building distributed applications using publish-subscribe, request-reply and multicast messaging. It is used in financial trading and other real-time systems where many programs must exchange data rapidly and reliably.

Rendezvous concept

• Based on subject-based addressing: a message carries a hierarchical subject name such as STOCK.NEPSE.NABIL.PRICE. A publisher sends to a subject; any program that subscribes to it (wildcards allowed) receives the message. Sender and receiver do not know each other's address, so they are loosely coupled.
• Communication is anonymous and many-to-many; supported styles: publish-subscribe (one to many), request-reply, and certified delivery for guaranteed messages.
• Messages are self-describing, with typed fields, so different languages and platforms can exchange them.
• Reliable multicast over the LAN gives high throughput and low latency.

Implementation

 App --> RV API --> rvd daemon ==== network ====> rvd --> App
 (publish)  (client library)   (multicast/UDP)   (subscribe)

1. Each machine runs the Rendezvous daemon (rvd). Applications use the RV client library to talk to the local daemon.
2. The daemon sends a published message by UDP broadcast/multicast on the network, and filters incoming messages by subject for local subscribers.
3. Reliability: messages carry sequence numbers. A receiving daemon that finds a gap sends a negative acknowledgement, and the sending daemon, which keeps recent messages for a short reliability interval (60 s by default), retransmits them. Order is kept without a central server.
4. Rendezvous router daemon (rvrd) passes messages across subnets and WANs; Certified delivery records messages in a ledger (usually a disk file) and retransmits them until every subscriber acknowledges them.
5. Fault tolerance uses a set of replicated programs, with one active member and standby members taking over on failure.