Have you got No ManagedConnections available error message ? well there are 4 possible cause to this problem.......

# 1  Your connection pool is too small

Increase the max number of connections in your Datasource .ds.xml file


# 2  Your threads are being starved by cpu

Incresing the blocking timeout from default 30000 in your Datasource ds.xml


# 3 You are not closing connections properly

Are you closing your connections in the finally method ? (If not your job is really in danger )

finally {
    if (resultSet != null)
    if (statement != null)


#4 You have hit a bug !

This is the most unlikely......anyway a couple of bugs existed with release 3.2.5 and earlier, so check the bug parade !

Check the following article to learn how to trace your Datasource connections: How to trace JDBC statements with JBoss and WildFly


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