Inspection of I/O Operations from System Call Traces using Directly-Follows-Graph

We aim to identify the differences in Input/Output(I/O) behavior between multiple user programs in terms of contentions for system resources by inspecting the I/O requests made to the operating system. A typical program issues a large number of I/O requests to the operating system, thereby making the process of inspection challenging. In this paper, we address this challenge by presenting a methodology to synthesize I/O system call traces into a specific type of directed graph, known as the Directly-Follows-Graph (DFG). Based on the DFG, we present a technique to compare the traces from multiple programs or different configurations of the same program, such that it is possible to identify the differences in the I/O requests made to the operating system. We apply our methodology to the IOR benchmark, and compare the contentions for file accesses when the benchmark is run with different options for file output and software interface.