[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-6891) Hibernate is not reusing connections from the pool

Hibernate is not reusing connections from the pool -------------------------------------------------- Key: HHH-6891 URL: https://hibernate.onjira.com/browse/HHH-6891 Project: Hibernate ORM Issue Type: Bug Components: core Affects Versions: 4.0.0.CR7 Environment: Hibernate 4, MySQL 5.6 Reporter: Mat Banik Labels: c3p0, dbcp, hibernate Attachments: test_case.zip I have tried two connection pool providers C3P0 and Commons DBCP. Both are the most current versions. Everything starts fine. And data is loading from database as expected. But with C3P0 when left to defaults everything stops when maximum of 15 connections are reached. Nothing is freed up and the application behaves like it has memory leak. Here is bottom of log output 2011-12-13/17:21:55.167/EST [http-bio-80-exec-2] DEBUG begin 2011-12-13/17:21:55.167/EST [http-bio-80-exec-2] DEBUG Obtaining JDBC connection 2011-12-13/17:21:55.167/EST [http-bio-80-exec-2] DEBUG acquire test -- pool is already maxed out. [managed: 15; max: 15] 2011-12-13/17:21:55.167/EST [http-bio-80-exec-2] DEBUG awaitAvailable(): com.mchange.v2.c3p0.impl.NewPooledConnection@46f0decc 2011-12-13/17:21:55.167/EST [http-bio-80-exec-2] DEBUG trace com.mchange.v2.resourcepool.BasicResourcePool@9671641 [managed: 15, unused: 0, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@46f0decc) With Commons DBCP everything work as well until when maximum connections are reached and than it throws exception: org.springframework.orm.hibernate4.HibernateJdbcException: JDBC exception on Hibernate data access: SQLException for SQL [n/a]; SQL state [null]; error code [0]; Could not open connection; nested exception is org.hibernate.exception.GenericJDBCException: Could not open connection org.springframework.orm.hibernate4.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:165) org.springframework.orm.hibernate4.HibernateExceptionTranslator.convertHibernateAccessException(HibernateExceptionTranslator.java:50) org.springframework.orm.hibernate4.HibernateExceptionTranslator.translateExceptionIfPossible(HibernateExceptionTranslator.java:37) org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:58) org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:163) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)