Measurement correlator  

A measurement correlator that provides the measurement interface described in section  was implemented in Java. To allow easy access to the measurement correlator from both the instrumented application and the instrumented libraries without having to pass a reference, an additional class was implemented, providing the measurement interface using static methods.

The measurement correlator uses a hash table to map Java threads to instances of user transactions. Every time the measurement correlator is called, the appropriate user transaction can be determined from the hash table using the thread of the caller. Current system time is determined and stored in combination with further information in a vector. Regularly, a low priority thread is activated, sending the information to the management agent.