title: XA error: XAResource.XAER_RMFAIL start() failed on resource Resource manager is unavailable
body: <p>I developed an application on Weblogic 11g and configured a data source to connect Oracle 11g.</p>
  
  <p>When I start the application, I got an error, anyone have the ideas?</p>
  
  <pre><code>java.sql.SQLException: Unexpected exception while enlisting XAConnection java.sql.SQLException: XA error: XAResource.XAER_RMFAIL start() failed on resource 'My_DataSource': XAER_RMFAIL : Resource manager is unavailableoracle.jdbc.xa.OracleXAException
              at oracle.jdbc.xa.OracleXAResource.checkError(OracleXAResource.java:1099)
              at oracle.jdbc.xa.client.OracleXAResource.start(OracleXAResource.java:238)
              at weblogic.jdbc.wrapper.VendorXAResource.start(VendorXAResource.java:50)
              at weblogic.jdbc.jta.DataSource.start(DataSource.java:722)
              at weblogic.transaction.internal.XAServerResourceInfo.start(XAServerResourceInfo.java:1228)
              at weblogic.transaction.internal.XAServerResourceInfo.xaStart(XAServerResourceInfo.java:1161)
              at weblogic.transaction.internal.XAServerResourceInfo.enlist(XAServerResourceInfo.java:282)
              at weblogic.transaction.internal.ServerTransactionImpl.enlistResource(ServerTransactionImpl.java:507)
              at weblogic.transaction.internal.ServerTransactionImpl.enlistResource(ServerTransactionImpl.java:434)
              at weblogic.jdbc.jta.DataSource.enlist(DataSource.java:1592) 
  </code></pre>