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POHow to avoid MySQL connection timeout errors with EclipseLink?
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  1. POHow to avoid MySQL connection timeout errors with EclipseLink?
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    copied!<p>MySQL closes a connection after a certain time if nothing happens (<a href="http://dev.mysql.com/doc/refman/5.1/en/gone-away.html" rel="nofollow">8 hours by default</a>). The time can be influenced by the wait_timeout variable in the configuration.</p> <p>I have an Eclipse RCP application where I use EclipseLink as persistence framework and I get an error when the client exceeds the timeout:</p> <pre><code> 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... </code></pre> <p>I tried to set autoReconnect/autoReconnectForPools=true but this does not help. </p> <p>Thanks</p> <p><strong>EDIT</strong></p> <p>In my persistence.xml I have the following properties set:</p> <pre><code> &lt;property name="eclipselink.jdbc.read-connections.max" value="10" /&gt; &lt;property name="eclipselink.jdbc.cache-statements" value="true" /&gt; &lt;property name="eclipselink.jdbc.read-connections.shared" value="true" /&gt; </code></pre> <p>The rest of the configuration is done in the code:</p> <pre><code> Map&lt;Object, Object&gt; 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); </code></pre>
 

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