title: Apache Tomcat Threads in WAITING State with 100% CPU utilisation
body: <p>The application, when subjected to load, sometimes, utilises 100%.</p>
  
  <p>doing a <code>kill -quit &lt;pid&gt;</code> showed 1100+ threads in waiting state as:</p>
  
  <pre><code>Full thread dump Java HotSpot(TM) 64-Bit Server VM (16.3-b01 mixed mode):
  
  "http-8080-1198" daemon prio=10 tid=0x00007f17b465c800 nid=0x2061 in Object.wait() [0x00007f1762b6e000]
     java.lang.Thread.State: WAITING (on object monitor)
          at java.lang.Object.wait(Native Method)
          - waiting on &lt;0x00007f17cb087890&gt; (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
          at java.lang.Object.wait(Object.java:485)
          at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
          - locked &lt;0x00007f17cb087890&gt; (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
          at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
          at java.lang.Thread.run(Thread.java:619)
  
  "http-8080-1197" daemon prio=10 tid=0x00007f17b465a800 nid=0x2060 in Object.wait() [0x00007f1762c6f000]
     java.lang.Thread.State: WAITING (on object monitor)
          at java.lang.Object.wait(Native Method)
          - waiting on &lt;0x00007f17cb14f460&gt; (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
          at java.lang.Object.wait(Object.java:485)
          at org.apache.tomcat.util.net.JIoEndpoint$Worker.await(JIoEndpoint.java:458)
          - locked &lt;0x00007f17cb14f460&gt; (a org.apache.tomcat.util.net.JIoEndpoint$Worker)
          at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:484)
          at java.lang.Thread.run(Thread.java:619)
  ............
  </code></pre>
  
  <p>The state does not change even when the application-context is undeployed OR the DB is restarted.</p>
  
  <p>Please suggest a probable cause.</p>
  
  <p><strong>App Server: Apache Tomcat 6.0.26</strong></p>
  
  <p><strong>Max Threads: 1500</strong></p>
  
  <p><strong>Threads in WAITING state : 1138</strong></p>