How to avoid MySQL connection timeout errors with EclipseLink?

Question

MySQL closes a connection after a certain time if nothing happens (8 hours by default). The time can be influenced by the wait_timeout variable in the configuration.

I have an Eclipse RCP application where I use EclipseLink as persistence framework and I get an error when the client exceeds the timeout:

    Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: 
       No operations allowed after connection closed.
   at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
   ...
   at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
   at com.mysql.jdbc.Util.getInstance(Util.java:386)
       ...
   com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException
   ...
       org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor...

I tried to set autoReconnect/autoReconnectForPools=true but this does not help.

Thanks

EDIT

In my persistence.xml I have the following properties set:

    <property 
      name="eclipselink.jdbc.read-connections.max"
      value="10" />
    <property 
      name="eclipselink.jdbc.cache-statements" 
      value="true" />
    <property 
      name="eclipselink.jdbc.read-connections.shared"
      value="true" />

The rest of the configuration is done in the code:

    Map<Object, Object> map = ...
    map.put(PersistenceUnitProperties.JDBC_URL,...);
    map.put(PersistenceUnitProperties.JDBC_USER,...);
    map.put(PersistenceUnitProperties.JDBC_PASSWORD, ...);
    map.put(PersistenceUnitProperties.JDBC_DRIVER,  ...);
    map.put(PersistenceUnitProperties.CLASSLOADER, this.getClass()
            .getClassLoader());
    map.put(PersistenceUnitProperties.TARGET_DATABASE, "MySQL");
    entityManagerFactory = new PersistenceProvider()
            .createEntityManagerFactory("...", map);

Answer 1

EclipseLink should auto reconnect dead connections. EclipseLink will trap the error, test the connection and if dead reconnect and possibly retry the query (if outside a transaction).

But this depends on what connection pooling you are using, what is your persistence.xml.