Increase Janus performance with Streaming plugin

General
1

Hi everyone,
we are using Janus with the streaming plugin. When we launch one video stream, we receive 300-400 listeners without errors. If there are more listeners, we are starting to receive errors: ‘Discarding too old outgoing packet’.

When we set the number of processing threads in config according to the number of CPUs, we receive a limit of 500-600 listeners.

Currently, we are using several instances of Janus as horizontal scaling, but our goal is to get 900-1000 listeners on one Janus instance. Are there any recommendations for tuning Janus and Linux to achieve maximum Janus performance in the streaming plugin on single instance?

2

Use helper threads. The Streaming plugin documentation will explain how to enable them.

3
  • Well done, you have already configured event loops according to the number of cpus
  • 1 or 2 helper threads could help decoupling mountpoint rtp socket polling and packets dispatching, but your mileage may vary (please test and report back, it might be interesting for others too!)
  • Use compilation flags intended for production (e.g. “-Ofast -march=native -flto”)
  • Limit the verbosity of logs
  • Tune the process priority through Unix “nice” value
  • Perform a profiling of the server under load (with debugging flags “-Og -fno-omit-frame-pointer -g3 -ggdb3”) and try to discover what are the hot paths. This will be very interesting and might lead to a code refactoring/optimization if you share the data (e.g. a flamegraph)