MySQL ARM 4.0 instrumentation

To support real end-to-end web-measurements we instrumented the popular MySQL database with the ARM 4.0 C API. MySQL's primary interface is a client shared library called libmysqlclient.so. Within that library there exists several C API calls. The most important one is mysql_real_query(). This C function has to be used to execute any SQL statement within MySQL. Therefore we instrumented exactly this call. Here is a brief description of the measurement made by the instrumentation:

• Currently only one ARM transaction is used called Query and is registered with the ARM application called MySQL.
• The SQL statement is attached to the ARM transaction measurement using ARM properties.
• Parent correlator can be passed using the ARM_CORRELATOR environment variable.