Opportunistic evaluation of communication link loads

Algorithms for measuring the loads on the communication links in a distributed system are presented. Timestamped messages are used to measure latencies across physical and virtual links in the system. The algorithms do not generate any additional message traffic. Instead, load measurement information is opportunistically piggybacked onto application messages. The link load values can be used to initiate process migration and for dynamic flow control. An example of how loads on virtual links may be measured is given