title: rack-timeout: turn off info/active logging
body: <p>With the <a href="https://github.com/heroku/rack-timeout" rel="noreferrer" title="rack-timeout gem">rack-timeout</a> gem installed how is it possible to display ERROR only related logs? For example I would like to avoid having the below in my logs:</p>
  
  <p><code>
  source=rack-timeout id=8a11a8ac3dadb59a4f347d8e365faddf timeout=20000ms service=0ms state=active
  source=rack-timeout id=8a11a8ac3dadb59a4f347d8e365faddf timeout=20000ms service=49ms state=completed
  source=rack-timeout id=ee947d4a291d02821ab108c4c127f555 timeout=20000ms state=ready
  </code></p>
  
  <p>The following did not work:
  <code>Rack::Timeout.unregister_state_change_observer(:active)</code></p>
  
  <p>The below may be on the right path but I'm having trouble testing:</p>
  
  <p><code>Rack::Timeout::Logger.level  = Logger::ERROR</code></p>