This report is a survey of monitoring and event detection in distributed fault-tolerant real-time systems, as used in primarily active database systems, for testing and debugging purposes. It contains a brief overview of monitoring in general, with examples of how software systems can be instrumented in a distributed environment, and of the active database area with additional constraints of real-time discussed. The main part is a survey of event monitoring mostly taken from the active database area with additional discussion concerning distribution and fault-tolerance. Similarities between testing and debugging distributed real-time systems are described.