Distributed Network Monitoring and Debugging with SwitchPointer

Monitoring and debugging large-scale networks remains a challenging problem. Existing solutions operate at one of the two extremes-systems running at end-hosts (more resources but less visibility into the network) or at network switches (more visibility, but limited resources). We present SwitchPointer, a network monitoring and debugging system that integrates the best of the two worlds. SwitchPointer exploits end-host resources and programmability to collect and monitor telemetry data. The key contribution of SwitchPointer is to efficiently provide network visibility by using switch memory as a "directory service"-each switch, rather than storing the data necessary for monitoring functionalities, stores pointers to end-hosts where relevant telemetry data is stored. We demonstrate, via experiments over real-world testbeds, that SwitchPointer can efficiently monitor and debug network problems, many of which were either hard or even infeasible with existing designs.