Recent rapid scale out of high performance computing systems has rapidly and continuously increased the scale and complexity of the interconnects. As a result, current static and over-provisioned interconnects are becoming cost-ineffective. Against this background, we have been working on the integration of network programmability into the interconnect control, based on the idea that dynamically controlling the packet flow in the interconnect according to the communication pattern of applications can increase the utilization of interconnects and improve application performance. Interconnect simulators come in handy especially when investigating the performance characteristics of interconnects with different topologies and parameters. However, little effort has been put towards the simulation of packet flow in dynamically controlled interconnects, while simulators for static interconnects have been extensively researched and developed. To facilitate analysis on the performance characteristics of dynamic interconnects, we have developed PFAnalyzer. PFAnalyzer is a toolset composed of PFSim, an interconnect simulator specialized for dynamic interconnects, and PFProf, a profiler. PFSim allows interconnect researchers and designers to investigate congestion in the interconnect for an arbitrary cluster configuration and a set of communication patterns collected by PFProf. PFAnalyzer is used to demonstrate how dynamically controlling the interconnects can reduce congestion and potentially improve the performance of applications.
