On-line Avoidance of the Intrusive Effects of Monitoring on Runtime Scheduling Decisions

Distributed programs are often instrumented for collecting information to assist in analyzing the behavior of an application. However, the act of monitoring a process introduces intrusive overhead that delays the times at which actions occur in a monitored execution in comparison to the times at which they occur in an unmonitored execution. These delays can alter the actions of individual processes and the behavior of the system as a whole. The overall behavior of process scheduling is determined by the choices a scheduler makes in terms of when particular processes will be given access to the processor. Monitoring introduced delays can result in different scheduling choices being made which can in turn lead to changes in the behavior of processes throughout the distributed system. This paper presents intrusion removal techniques which are designed to accommodate monitoring delays in an attempt to minimize the intrusion on the scheduling and execution behavior of the monitored computat..