Abstract

We propose a rule-based language, Netlog, to express distributed applications such as communication protocols or P2P applications in a declarative manner. The language extends Datalog with communication primitives, as well as aggregation and non-deterministic constructs, standard in network applications. Our contribution is twofold. First we dene a sound distributed xpoint semantics, which takes explicitly into account the in-node behavior as well as the  communication between nodes, and solves semantic problems raised in declarative networking. Second, we show that syntactic restrictions over the programs can ensure polynomial bounds on the complexity (time and message) of the distributed execution. The language has been implemented and runs over a virtual machine, Netquest, which relies on a DBMS. Netlog programs are partly compiled into SQL queries, which makes them portable over heterogeneous architecture.