Lithos submits metrics via a cantal-compatible protocol.

All metrics usually belong to lithos’s cgroup, so for example in graphite you can find them under cantal.<cluster-name>.<hostname>.lithos.groups.*. Or you cand find them without this prefix in http://hostname:22682/local/process_metrics without a prefix.

In the following description we skip the common prefix and only show metric names.

Metrics of lithos master process:

  • master.restarts (counter) amount of restarts of a master process. Usually restart equals to configuration reload via lithos_switch or any other way.
  • master.sandboxes (gauge) number of sandboxes configured
  • master.containers (gauge) number of containers (processes) conigured
  • master.queue (gauge) length of the internal queue, the queue consists of processes to run and hanging processes to kill

Per-process metrics:

  • processes.<sandbox_name>.<process_name>.started – (counter) number of times process have been started
  • processes.<sandbox_name>.<process_name>.deaths – (counter) number of times process have exited for any reason
  • processes.<sandbox_name>.<process_name>.failures – (counter) number of times process have exited for failure reason, for whatever reason lithos thinks it was failure. See Determining Failure
  • processes.<sandbox_name>.<process_name>.running – (gauge) number of procesess that are currently running (was started but not yet found to be exited)

Global metrics for all sandboxes and containers:

  • containers.started – (counter) same as for processes.* but for all containers
  • containers.deaths – (counter) see above
  • containers.failures – (counter) see above
  • containers.running – (gauge) see above
  • containers.unknown – (gauge) number of child processes of lithos that are found to be running but do not belong to any of the process groups known to lithos (they are being killed, and they are probably from deleted configs)

Determining Failure

Currently there are two kinds of process death that are considered non-failures:

  1. Processes that had been sent SIGTERM signal to (with any exit status) or ones dead on SIGTERM signal are considered non-failed.
  2. Processes exited with one of the exit codes specified in normal-exit-codes