AGIOS: Application-Guided I/O Scheduling for Parallel File Systems

In this paper, we improve the performance of server-side I/O scheduling on parallel file systems by transparently including information about the applications´ access patterns. Server-side I/O scheduling is a valuable tool on multiapplication scenarios, where the applications´ spatial locality suffers from interference caused by concurrent accesses to the file system. We present AGIOS, an I/O scheduling library for parallel file systems. We guide scheduler´s decisions by including information about the applications´ future requests. This information is obtained from traces generated by the scheduler itself, without changes in application or file system. Our approach shows performance improvements under different workloads of 46.3% on average when compared to a scenario without an I/O scheduler, and of 25.1% when compared to a scheduler which does not use information about future accesses.