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Title: Knowledge-based monitoring and control of distributed systems

Miscellaneous ·
OSTI ID:5827949

As distributed systems and applications become more numerous and more complex, it becomes increasingly important to develop tools and techniques for studying and understanding their behavior in a systematic way. Monitoring and control (M and C) refers to the process of collecting information about a system, interpreting it, and finally using it to affect system behavior. The author shows that a knowledge-based approach is both necessary and appropriate for M and C of complex message-based distributed systems. Production rule systems have been used with success in many diagnostic situations, however the declarative representation style they impose does not efficiently preserve the important temporal relationships between packets. To achieve good performance, he has augmented the traditional purely declarative rule system approach with cached temporal linkage information and fast procedural analysis routines for dealing with the common operation of localized search. M and C can be viewed as a signal processing task, where packet traces comprise the signal to be analyzed. A blackboard approach has been successfully applied to other signal processing problems, as in Hearsay and HASP; he has found that it is also appropriate in the M and C domain. However, scheduling or search control in blackboard systems is highly application-specific and must be tuned for M and C applications. He has developed multi-level weighted -search control to overcome some of the scheduling problems that are encountered in domains such as M and C where shallow heuristic knowledge predominates. His ideas have been developed and refined in the context of two implementations of monitoring and control expert systems: an automated TCP/IP network protocol analyst and a system for both performing Time Warp distributed simulations and analyzing the results.

Research Organization:
Stanford Univ., CA (USA)
OSTI ID:
5827949
Resource Relation:
Other Information: Thesis (Ph.D)
Country of Publication:
United States
Language:
English