5.4. Rule Reloads

Suricata can be told to reloads it’s rules without restarting.

This works by sending Suricata a signal or by using the unix socket. When Suricata is told to reload the rules these are the basic steps it takes:

  • Load new config
  • Load new rules
  • Construct new detection engine
  • Swap old and new detection engines
  • Make sure all threads are updated
  • Free old detection engine

Suricata will continue to process packets normally during this process. Keep in mind though, that the system should have enough memory for both detection engines.

Signal:

kill -USR2 $(pidof suricata)

Unix socket has two method for rules reload.

Blocking reload

suricatasc -c reload-rules

Non blocking reload

suricatasc -c ruleset-reload-nonblocking

It is also possible to get information about the last reload via dedicated commands. See Commands in standard running mode for more information.