title: high cpu usage mysql
body: <p>I've started to see very high cpu usage on mysql on my CentOS server.</p>
  
  <p>It used to run at between 20%-30% but now will spike into the 400% at times.</p>
  
  <pre><code>PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  9169 mysql     20   0 2232m  66m 6816 S 140.6  0.9  17:37.03 mysqld                      
  </code></pre>
  
  <p>when i do a show processlist i dont see much running</p>
  
  <pre><code>mysql&gt; show processlist;
  +-------+------+-----------+----------+---------+------+-------+------------------+
  | Id    | User | Host      | db       | Command | Time | State | Info             |
  +-------+------+-----------+----------+---------+------+-------+------------------+
  |    53 | sqluser | localhost | mydns    | Sleep   |    0 |       | NULL             |
  |   449 | sqluser | localhost | DB1  | Sleep   |    0 |       | NULL             |
  | 16151 | sqluser | localhost | DB2 | Sleep   |  105 |       | NULL             |
  | 16473 | sqluser | localhost | DB2 | Sleep   |   61 |       | NULL             |    
  | 16641 | sqluser | localhost | DB2 | Sleep   |   39 |       | NULL             |
  | 16729 | sqluser | localhost | DB2 | Sleep   |   29 |       | NULL             |
  | 16733 | sqluser | localhost | DB2 | Sleep   |   29 |       | NULL             |
  | 16815 | sqluser | localhost | DB2 | Sleep   |   15 |       | NULL             |
  | 16867 | sqluser | localhost | DB2 | Sleep   |    9 |       | NULL             |
  | 16886 | sqluser | localhost | NULL     | Query   |    0 | NULL  | show processlist |
  | 16910 | sqluser | localhost | DB2 | Sleep   |    5 |       | NULL             |
  | 16919 | sqluser | localhost | DB1  | Sleep   |    4 |       | NULL             |
  | 16935 | sqluser | localhost | DB1  | Sleep   |    2 |       | NULL             |
  | 16937 | sqluser | localhost | DB1  | Sleep   |    2 |       | NULL             |
  | 16939 | sqluser | localhost | DB1  | Sleep   |    1 |       | NULL             |
  | 16941 | sqluser | localhost | DB1  | Sleep   |    1 |       | NULL             |
  | 16951 | sqluser | localhost | DB1  | Sleep   |    1 |       | NULL             |
  | 16952 | sqluser | localhost | DB2 | Sleep   |    1 |       | NULL             |
  | 16955 | sqluser | localhost | DB1  | Sleep   |    1 |       | NULL             |
  | 16960 | sqluser | localhost | DB1  | Sleep   |    0 |       | NULL             |
  | 16965 | sqluser | localhost | DB1  | Sleep   |    0 |       | NULL             |
  +-------+------+-----------+----------+---------+------+-------+------------------+
  21 rows in set (0.00 sec)
  </code></pre>
  
  <p>Is there anything else i can do to see what is causing such high usage?</p>