title: How does HikariCP handle incomplete JDBC transactions?
body: <p>Yesterday I came across <a href="https://github.com/brettwooldridge/HikariCP">HikariCP</a> and spent the whole night studying it. I'm really impressed with the amount of detail and effort put into <a href="https://github.com/brettwooldridge/HikariCP/wiki/Down-the-Rabbit-Hole">fine tuning</a> its implementation and design. 
  Straight to the point, I could not determine how it actually deals with connections that are checked back into the pool with their <code>autoCommit</code> set to <code>false</code>, while neither <code>commit()</code> nor <code>rollback()</code> is issued on them, for example, due to an exception. This potentially can be the source of many serious transactional problems for the next requester that expects a fresh connection but unfortunately receives this connection with its dangling transaction state.</p>
  
  <p>While C3P0 and Tomcat's JDBC pool have some of these so called <strong>Knobs</strong> for this very purpose (through configuration or interception), I could not find anything in HikariCP's documentation or support group. Please correct me if I'm wrong, but writing a simple unit test showed me that the pool does nothing about this.</p>
  
  <p>I need to know if this observation is actually correct and I'm not missing anything about it. Also, if there is any plan for addressing this in HikariCP since it is critical for me.</p>
  
  <p>Thanks.</p>