Hello,
I'm using Hibernate with MySQL and c3p0, and when the MySQL connection expires after 8 hours (wait_timeout
), Hibernate is unable to reconnect and i get the following exception:
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.io.EOFException
STACKTRACE:
java.io.EOFException
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1963)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2375)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2874)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1623)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1715)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3249)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1268)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1403)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1812)
at org.hibernate.loader.Loader.doQuery(Loader.java:697)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
at org.hibernate.loader.Loader.doList(Loader.java:2232)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2129)
at org.hibernate.loader.Loader.list(Loader.java:2124)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1149)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
This is the hibernate.cfg:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mydb</property>
<property name="hibernate.connection.username">username</property>
<property name="hibernate.connection.password">password</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<property name="hibernate.query.substitutions">true 1, false 0</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.hbm2ddl.auto">validate</property>
<property name="hibernate.connection.autocommit">false</property>
<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
<property name="hibernate.c3p0.min_size">3</property>
<property name="hibernate.c3p0.max_size">10</property>
<property name="hibernate.c3p0.timeout">180</property>
<property name="hibernate.c3po.max_idle_time">180</property>
<property name="hibernate.c3p0.idle_test_period">300</property>
<property name="hibernate.c3p0.acquire_increment">3</property>
<!-- My mappings here -->
</session-factory>
</hibernate-configuration>
and this is my c3p0.properties file:
c3p0.preferredTestQuery=SELECT 1
UPDATE:
Below the log file:
INFO - com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getPoolManager(462) | Initializing c3p0 pool... com.mchange.v2.c3p0.PoolBackedDataSource@6df9572
c [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@7eeb0844 [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetr
yDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassNam
e -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation
-> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> jbnj238aq9q7lecas8ck|79b0d33c, idleConnectionTestPeriod -> 300, initialPoolSize -> 3,
maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 180, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 10, maxStatements -> 0, maxState
mentsPerConnection -> 0, minPoolSize -> 3, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@8ed91d5 [ description -> null, driverClass -> null
, factoryClassLocation -> null, identityToken -> jbnj238aq9q7lecas8ck|445ead9d, jdbcUrl -> jdbc:mysql://localhost:3306/mydb, properties -> {user=******, p
assword=******, autocommit=false} ], preferredTestQuery -> SELECT 1, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false,
unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, iden
tityToken -> jbnj238aq9q7lecas8ck|26796e1c, numHelperThreads ->
3 ]
Any tip is appreciated.
Thanks