title: systemd restart service on watchdog does terminate previous hanged instance
body: <p>I'm trying to setup systemd service configuration to restart service on watchdog failure. If my application does not call sd_notify() in time, systemd spawns new instance.
  However, previus instance is not killed. After some time, I have many instances of my application running.</p>
  
  <pre><code>$ systemctl status my-daemon.service
  
    Loaded: loaded (/lib/systemd/system/my-daemon.service; disabled)
    Active: active (running) since Tue, 26 Aug 2014 10:27:46 +0000; 7s ago
  Main PID: 1433 (attendance-syst)
    CGroup: name=systemd:/system/my-daemon.service
        ├ 1281 /usr/local/bin/my-daemon
        ├ 1384 /usr/local/bin/my-daemon
        ├ 1407 /usr/local/bin/my-daemon
        └ 1433 /usr/local/bin/my-daemon
        ...
  </code></pre>
  
  <p>This is part of my service file:</p>
  
  <pre><code>[Service]
  ExecStart=/usr/local/bin/my-daemon
  TimeoutStopSec=5
  WatchdogSec=10
  Restart=on-failure
  </code></pre>
  
  <p>How can i configure systemd to kill instances which fails on watchdog?</p>
  
  <p>I have already read manual <a href="http://www.freedesktop.org/software/systemd/man/systemd.service.html" rel="nofollow">page</a> but it didn't help me.</p>
  
  <p>I thought <code>Restart=on-failure</code> shall restart hanged process by default...</p>