title: Can MySQL reboot the server its running on?
body: <p>I am running a MySQL on Ubuntu 12.04 on Amazon EC2. I understand that the memory given to this instance is pretty small (actually 15G) for the kind of workload I run with MySQL. Few days back I noticed that server was rebooted. I checked <code>/var/log/messages</code>, <code>/var/log/kern.log</code> and then <code>lastlog</code>. I found out from the <code>last</code> command that the system was rebooted by the <code>reboot</code> pseudo-user.</p>
  
  <p>The <code>/proc/sys/vm/overcommit_ratio</code> is set to 50, which means that the Linux will commit 50% more memory to the running processes. I have not created a swap, so I am sure that at times, MySQL will request for more memory than the available physical RAM which it won't get. Also, I have not set kernel panic in the <code>/etc/sysctl.conf</code>. This instance is used as a database server and no other processes other than a cron (used to backup MySQL data) that runs every hour. The cron was not scheduled to run at the time when the reboot happened.</p>
  
  <p>So, my question is -</p>
  
  <p>Can a overloaded MySQL reboot the instance it is running on when it ran out of memory?</p>
  
  <p>I am trying to understand what might have led to the server reboot.</p>