1. A method to process application performance data, comprising the steps of: injecting an agent into a monitored application; capturing a byte code of the monitored application by the agent; sending the captured byte code of the monitored application to a monitoring server external to the monitored application; generating instrumented byte code from the captured byte code; providing the instrumented byte code to the monitored application; loading the instrumented byte code by the monitored application; generating measurement data from the instrumented byte code; writing the measurement data to a data set of fixed size.