I am using hibernate 3, c3p0 9.1.2, Oracle 11g in my application. If I restart the Oracle then the stale connections are not getting refresh and I am getting exception "java.sql.SQLRecoverableException: Closed Connection". Below is my hibernate.cfg.xml.
I am a beginner in Hibernate API. Can you please suggest how to configure hibernate to automatically refresh the stale connections on a specified time.
Here is my hibernate.cfg.xml
oracle.jdbc.driver.OracleDriver jdbc:oracle:thin:@localhost:1521:ems emsman
<property name="hibernate.c3p0.idle_test_period">60</property> <!-- seconds --> <property name="hibernate.c3p0.min_size">5</property> <property name="hibernate.c3p0.max_size">20</property> <property name="hibernate.c3p0.timeout">1800</property> <property name="hibernate.c3p0.max_statements">50</property> <property name="show_sql">false</property> <property name="dialect">org.hibernate.dialect.OracleDialect</property> <property name="c3p0.validate">true</property> <mapping resource="<package-name>/GroupOpWorkflow.hbm.xml"/> <mapping resource="<package-name>/GroupOperation.hbm.xml"/> <mapping resource="<package-name>/GroupOpNode.hbm.xml"/> <mapping resource="<package-name>/NodeStatusLog.hbm.xml"/> </session-factory>
It's c3p0, your database connection pool, that you need to configure - not hibernate. Try setting idleConnectionTestPeriod and an appropriate preferredTestQuery, e.g., select 1 from dual. The validate property has been deprecated and it's recommended that you not use that.
See http://community.jboss.org/wiki/HowToConfigureTheC3P0ConnectionPool for more information. You'll get the most control if you create a c3p0.properties file in WEB-INF/classes but you need to make sure not to override those properties in your hibernate.cfg.xml.
After gone through the document { http://community.jboss.org/wiki/HowToConfigureTheC3P0ConnectionPool } I found C3P0 was not a all used by hibernate. So wrote a new C3P0 xml file and used the below system properties: C3P0_SYS_PROPS="-Dcom.mchange.v2.c3p0.cfg.xml=<FILE-PATH>/c3p0-config.xml -Dcom.mchange.v2.log.MLog=com.mchange.v2.log.FallbackMLog -Dcom.mchange.v2.log.FallbackMLog.DE FAULT_CUTOFF_LEVEL=WARNING" So here is the final working configuration hibernate.cfg.xml <session-factory> <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property> <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:ems</property> <property name="hibernate.connection.username">emsman</property> <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> <property name="hibernate.connection.autoReconnect">true</property> <property name="show_sql">false</property> <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property> <property name="hibernate.c3p0.idle_test_period">300</property> <!-- In seconds --> <property name="hibernate.c3p0.min_size">5</property> <property name="hibernate.c3p0.max_size">20</property> <property name="hibernate.c3p0.timeout">1800</property> <property name="hibernate.c3p0.max_statements">50</property> ..... <c3p0-config> <default-config> <!-- Configuring Connection Testing --> <!-- property name="automaticTestTable">TEST_EMS_HIBERNATE_CONN</property --> <property name="checkoutTimeout">0</property> <property name="testConnectionOnCheckout">true</property> <property name="testConnectionOnCheckin">false</property> <property name="preferredTestQuery">SELECT 1 from dual</property> <!-- Configuring Recovery From Database Outages --> <property name="acquireRetryAttempts">0</property> <property name="acquireRetryDelay">1000</property> <property name="breakAfterAcquireFailure">false</property> <!-- Configuring to Debug and Workaround Broken Client Apps --> <property name="unreturnedConnectionTimeout">1800</property> <property name="debugUnreturnedConnectionStackTraces">true</property> </default-config> c3p0-config.xml <c3p0-config> <default-config> <!-- Configuring Connection Testing --> <!-- property name="automaticTestTable">TEST_EMS_HIBERNATE_CONN</property --> <property name="checkoutTimeout">0</property> <property name="testConnectionOnCheckout">true</property> <property name="testConnectionOnCheckin">false</property> <property name="preferredTestQuery">SELECT 1 from dual</property> <!-- Configuring Recovery From Database Outages --> <property name="acquireRetryAttempts">0</property> <property name="acquireRetryDelay">1000</property> <property name="breakAfterAcquireFailure">false</property> <!-- Configuring to Debug and Workaround Broken Client Apps --> <property name="unreturnedConnectionTimeout">1800</property> <property name="debugUnreturnedConnectionStackTraces">true</property> </default-config>
