Docs: Controlling the Daemon

Controlling the Daemon

The main daemon that runs on nodes keeps internal stats and supports reloading of agents, we provide a tool - mco controller - to interact with any running daemon from a client.

If all you want is to reload all the agents without restarting the daemon you can just send it signal USR1 and it will reload its agents.

You can send USR2 to cycle the log level through DEBUG to FATAL and back again, just keep sending the signal and look at the logs.

Details

The mco controller application allows you to:

  • Get stats for each mcollectived
  • Reload a specific agent
  • Reload all agents

Usage

Usage is like for any other client, you run mco controller from your management station and use filters to target just the nodes you need.

Statistics

This will show some basic statistics about the daemon:

% mco controller stats
Determining the amount of hosts matching filter for 2 seconds .... 1

                devel.your.com> total=22 replies=17 valid=22 invalid=0 filtered=0 passed=22

---- mcollectived controller summary ----
           Nodes: 1 / 1
      Start Time: Wed Feb 17 21:06:53 +0000 2010
  Discovery Time: 2010.40ms
      Agent Time: 53.13ms
      Total Time: 2063.53ms

Each stat means:

Statistic Meaning
total Total messages received from the middleware
replies Replies sent back
valid Messages that passed validity checks like the PSK
invalid Messages that could not be validated
filtered Messages that we received but that we did not reply to due to the filter

Reloading an agent

You can reload a specific agent if you’ve just copied a new one out and don’t want to restart the daemons:

% mco controller reload_agent --arg rpctest
Determining the amount of hosts matching filter for 2 seconds .... 1

                devel.your.com> reloaded rpctest agent

---- mcollectived controller summary ----
           Nodes: 1 / 1
      Start Time: Wed Feb 17 21:10:13 +0000 2010
  Discovery Time: 2004.02ms
      Agent Time: 57.65ms
      Total Time: 2061.67ms

Reloading all agent

Like the previous command but acts on all agents, this is the same as sending USR1 signal to the process:

% mco controller reload_agents
Determining the amount of hosts matching filter for 2 seconds .... 1

                devel.your.com> reloaded all agents

---- mcollectived controller summary ----
           Nodes: 1 / 1
      Start Time: Wed Feb 17 21:10:46 +0000 2010
  Discovery Time: 2006.71ms
      Agent Time: 182.45ms
      Total Time: 2189.16ms