Abstract

The second iteration of the TIME -EACM Middleware is called SBUS . We’re currently at the late design stage. Our target application is complex distributed sensor stream processing, such as in road traffic monitoring, although the architecture is intended to be general-purpose.

The design has an unusual structure which is decentralised (P2P) for scalability but retains most of the semantics of a centralised system. It attempts to unify all possible pairwise interaction patterns, including messages and RPC ’s, but most significantly supports stream-based communication.

It is specification-oriented, using XML schemas to describe API ’s. It has self-monitoring of component status, topology and performance. Access control is role-based. There is support for migration, replication, load balancing, failover, and flow control.

The requirement for reliable continuous operation of streams in the presence of failures, live topology changes and data format evolution has led to some interesting research questions.