title: How to setup an EJB timerDataSource in Open Liberty
body: <p>I try to deploy a Java EE Application containing several EJB Timer Services (with persistence=true). 
  The server complains that no datasource was defined:</p>
  
  <pre><code>Caused by: javax.ejb.EJBException: See nested exception; nested exception is: java.lang.IllegalStateException: The ejbPersistentTimer feature is enabled, but the defaultEJBPersistentTimerExecutor persistent executor cannot be resolved. The most likely cause is that the DefaultDataSource datasource has not been configured. Persistent EJB timers require a datasource configuration for persistence.
  </code></pre>
  
  <p>The ejbPersistentTimer-3.2 feature is turned on.
  I can not find an example how to configure such a datasource in the server.xml file</p>
  
  <p>I tried:</p>
  
  <pre><code>&lt;dataSource id="timerDataSource" jndiName="jdbc/timerDataSource"&gt;
  &lt;/dataSource&gt;
  
  &lt;databaseStore id="EJBTimerDatabaseStore"
      tablePrefix="EJBTimer_" dataSourceRef="timerDataSource" /&gt;
  &lt;persistentExecutor
      id="defaultEJBPersistentTimerExecutor"
      taskStoreRef="EJBTimerDatabaseStore" /&gt;
  </code></pre>
  
  <p>But this seems to be not enoght? Did I need to activate DerbyDB as a feature too?</p>