Exploiting program semantics for efficient instrumentation of distributed event recognitions

Event based monitors and debuggers for distributed systems automatically detect occurrences of user specified events that characterize the state of one or more processes in a distributed computation. The system monitors the occurrences of local events. Data pertaining to these occurrences is utilized to detect occurrences of distributed events which check the ordering or concurrency of local events that occur at different processes. The overhead of recognizing distributed events can be high, because of the need to capture, communicate, store and evaluate event information for analysis. This paper presents techniques that exploit program and event semantics to reduce the overhead of monitoring a distributed computation for ordered and concurrent events. Static analysis algorithms are presented that determine the minimal program instrumentation required to insure that adequate state and timing information are available to recognize every event occurrence