SC Conference - Activity Details

John M. May  (Lawrence Livermore National Laboratory)

Tuesday,  05:15PM - 07:00PM

Room Rotunda Lobby

Scripted I/O benchmarks record the I/O behavior of real applications by using an instrumentation library to trace I/O events and their timing. A replay engine can then reproduce these events at the specified time intervals from a script in the absence of the original application. This type of benchmark reproduces real-world workloads without the need to distribute, build, or run complex applications. To create a script that faithfully records an I/O workload, the instrumentation software must log only low-level I/O events, and it must measure inter-event times accurately. Library interposition and the strace utility are two simple techniques for instrumenting I/O system calls, but both have drawbacks. We have developed an I/O instrumentation library based on binary instrumentation to generate replay scripts. Our library allows accurate reproduction of application-specific I/O workloads. We present I/O time profiles from replay runs showing good agreement with the profiles of the original applications.