Speeding up a path-based policy language compiler

Abstract

Policy based network management has an increasing importance depending on the increasing importance of distributed large networks and the growing number of services that run on them. Policy languages, which enable users define policies in a formal language, are one of the main tools of policy management. Even though there are policy languages like PFDL or RPSL, none of them has the capability of a robust conflict detection and resolution focused on policy. A new Policy Language, Path-based Policy Language (PPL), has been developed recently. It encompasses as many of the features addressed in the other policy languages as possible, as well as providing means for testing policies for consistency and defining both static and dynamic policies. The most important, PPL provides the ability to detect and resolve conflicts between by translating policy rules into formal logic statement and checking them with a Prolog program. Even though in theory PPL seems to be a very high performance policy language, its current compiler has a performance bottleneck. In some cases the PPL compiler can not finish compilation and runs forever without returning any conflict results. This thesis focuses on the PPL compiler's performance bottleneck and introduces solutions speeding up the PPL compiler. The new PPL compiler achieves a reasonable compilation time for any configuration file for a network with 100 nodes while maintaining its ability to detect and resolve policy conflicts.