title: Relation between Oracle session and connection pool
body: <p>Let me explain the set up first.</p>
  
  <p>We have an oracle server running on a 2GB RAM machine. The Db instance has the init parameter "sessions" set to 160.</p>
  
  <p>We have the application deployed on Websphere 6.1. The connection pool settings is Min 50 and Max 150.</p>
  
  <p>When we run Load test on 40 Users (concurrent, using jMeter), everything goes fine.
  But when we increase the concurent users to Beyond 60, Oracle throws and exception that it is out of sessions.</p>
  
  <p>We checked the application for any connection leaks but could not find any.</p>
  
  <p>So does it mean that the concurrency of 40 is what this setup can take ? Is increasing the Oracle sessions/process the only way to obtain higher concurrency ? </p>
  
  <p>How exactly are the DB sessions and Connection in the Connection pool related ? In my understanding, the connections cannot exceed the sessions and so setting the Max Connection pool to more than sessions may not really matter. Is that correct ?</p>