Efficient online monitoring of web-service SLAs
Part of book or chapter of book, Conference object, Article
- Publisher: Association for Computing Machinery
If an organization depends on the service quality provided by\ud another organization it often enters into a bilateral service\ud level agreement (SLA), which mitigates outsourcing risks\ud by associating penalty payments with poor service quality.\ud Once these agreements are entered into, it becomes necessary\ud to monitor their conditions, which will commonly relate\ud to timeliness, reliability and request throughput, at runtime.\ud We show how these conditions can be translated into timed\ud automata. Acceptance of a timed word by a timed automaton\ud can be decided in quadratic time and because the timed\ud automata can operate while messages are exchanged at runtime\ud there is effectively only a linear run-time overhead. We\ud present an implementation to derive on-line monitors for\ud web services automatically from SLAs using an Eclipse plugin.\ud We evaluate the efficiency and scalability of this approach\ud using a large-scale case study in a service-oriented\ud computational grid.