Connection hangs after time of inactivity

Question

In my application, Spring manages connection pool for database access. Hibernate uses these connections for its queries. At first glance, I have no problems with the pool: i

Answer 1

We solved problem with similar symptoms which also turned out to be caused by a firewall.

We were able to work around the problem by changing the testWhileIdle connection pool property which prevents the connection from going idle and from the firewall shutting down the connection. See Apache commons dbcp BasicDataSource. Here is an exert from the configuration file, persistentce-context.xml that fixed the problem:

  true


  600000


  600000

Most likely we only need to add the testWhileIdle (false by default), but added the other two properties for good measure.

In our case, here are some of the logs which we were seeing. Notice in this debug logs, it would take 16 minutes to open the connection before the connection could be used and this is what caused everything to hang. There were no errors which made it hard to track down.

09-06-13 @ 16:36:34 [DEBUG] HibernateTransactionManager - Preparing JDBC Connection of Hibernate Session [org.hibernate.impl.SessionImpl@db17ab]
09-06-13 @ 16:36:34 [DEBUG] ConnectionManager - opening JDBC connection
09-06-13 @ 16:52:00 [DEBUG] DataSourceUtils - Setting JDBC Connection
09-06-13 @ 16:52:00 [DEBUG] JDBCTransaction - begin
09-06-13 @ 16:52:00 [DEBUG] JDBCTransaction - current autocommit status: true