Hibernate version: 3.1
Name and version of the database you are using: MySQL 4.1
Debug level Hibernate log excerpt: info
I'm using Apache Tomcat 5
---
Hello,
My connection timed out, so I thought I'd switch from the in-built pooling to C3P0. I copied the c3p0-0.9.0.jar file into the lib directory of WEB-INF, and set the following properties in the hibernate config file:
<property name="hibernate.c3p0.max_size">1</property>
<property name="hibernate.c3p0.min_size">0</property>
<property name="hibernate.c3p0.timeout">5000</property>
<property name="hibernate.c3p0.max_statements">100</property>
<property name="hibernate.c3p0.idle_test_period">300</property>
<property name="hibernate.c3p0.acquire_increment">2</property>
I restarted Tomcat, and in the logs I could see that C3P0 was recognized, and that it was used by Hibernate for pooling.
Then I tried to do one simple operation on the database. My Auth servlet contacts the database, and checks if the user exists or not, and if he does then returns OK. I've got an exception saying that the connection cannot be openned. Here's the stack trace:
Code:
ERROR - Servlet.service() for servlet Auth threw exception
org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:91)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:79)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:363)
at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:122)
at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:125)
at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57)
at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1309)
at com.myapp.servlets.Auth.doPost(Auth.java:36)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:825)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:738)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:526)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: com.mchange.v2.c3p0.PoolBackedDataSource@5ddb6e [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@269997 [ acquireIncrement -> 2, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 269997, idleConnectionTestPeriod -> 300, initialPoolSize -> 0, maxIdleTime -> 5000, maxPoolSize -> 1, maxStatements -> 100, maxStatementsPerConnection -> 0, minPoolSize -> 0, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@1947496 [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> 1947496, jdbcUrl -> jdbc:mysql://localhost/myapp, properties -> {user=******, password=******} ], preferredTestQuery -> null, propertyCycle -> 300, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, usesTraditionalReflectiveProxies -> false ], factoryClassLocation -> null, identityToken -> 5ddb6e, numHelperThreads -> 3 ] has been closed() -- you can no longer use it.
at com.mchange.v2.c3p0.PoolBackedDataSource.assertCpds(PoolBackedDataSource.java:234)
at com.mchange.v2.c3p0.PoolBackedDataSource.getPoolManager(PoolBackedDataSource.java:246)
at com.mchange.v2.c3p0.PoolBackedDataSource.getConnection(PoolBackedDataSource.java:94)
at org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:35)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:360)
... 21 more
Line 36 of Auth (where the exception occured) is as follows:
Code:
Transaction transaction = HibernateUtil.getSession().beginTransaction();
While the getSession() method returns a session like this:
Code:
sessionFactory.openSession()
I'm guessing the problem is with configuring C3P0. Could someone explain what I have to do here?
Thanks, Csaba
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