Abstract: A measurement system and method of instrumenting a computer program for efficiently monitoring the quality of service in a distributed processing environment are described. A plurality of interconnected network nodes in a computer system with an application process operating on each network node is provided. At least one intelligent sensor is associated with each application process. Each intelligent sensor selectively collects data about at least one of the network node upon which the associated application process operates and the associated application process. An observer is associated with each application process and filters out unchanged and zero values from the data collected by the at least one intelligent sensor. A collector is logically associated with each network node. The intervalized collected data is asynchronously received into the collector periodically pushed from the observer.