Is there any way to determine database connection pool size (connection in used/connection remaining in connection pool) programmatically? We am using Hibernate with C3P0.
We are facing issues while connecting to db. Following exception is thrown and the data is not saved in db.
1005,MA,19/09/11 09:39:14,com.novosys.gtw.business.frontend.SnapshotMessageBusiness.save, Major: Cannot open connection
org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142)
at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85)
at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1354)
at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:342)
at $Proxy0.beginTransaction(Unknown Source)
at com.novosys.gtw.util.base.BaseBusiness.save(BaseBusiness.java:199)
at com.novosys.gtw.business.backend.receivesnapshotmessage.filter.SaveMessageFilter.decode(SaveMessageFilter.java:102)
at org.apache.mina.filter.codec.demux.DemuxingProtocolCodecFactory$ProtocolDecoderImpl.doDecode(DemuxingProtocolCodecFactory.java:292)
at org.apache.mina.filter.codec.CumulativeProtocolDecoder.decode(CumulativeProtocolDecoder.java:133)
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:158)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648)
at com.novosys.gtw.business.backend.receivesnapshotmessage.filter.WhitelistFilter.messageReceived(WhitelistFilter.java:231)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648)
at com.novosys.gtw.business.backend.receivesnapshotmessage.filter.MoniterFilter.messageReceived(MoniterFilter.java:92)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(AbstractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilterChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceived(AbstractIoFilterChain.java:648)
at org.apache.mina.filter.executor.ExecutorFilter.processEvent(ExecutorFilter.java:220)
at org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(ExecutorFilter.java:264)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:78)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
... 31 more
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
... 34 more
We tried to resolve it by increasing connection pool size and also increasing no. of connections available at MySQL level, but of no use. We are now trying to sort of debug it to see if its due to connection pool size or due to MySQL connection size. We want to log no. of connection available/in use in connection pool size but could not get any help from google.
Environment: Java, Hibernate, C3P0, MySQL
Session session = null;
Transaction transaction = null;
try {
session = HibernateUtil.getSessionFactory(datasource).getCurrentSession();
transaction = session.beginTransaction();
// db save called here
session.getTransaction().commit();
} catch (Exception e) {
Logger.write(LoggerConstant.MAJOR_ERROR, e.getMessage(), e, methodName);
} finally {
try {
if ((transaction != null) && (transaction.isActive())) {
transaction.rollback();
}
} catch (Exception e) {
Logger.write(LoggerConstant.CRITICAL_ERROR, e.getMessage(), e, methodName);
}
try {
if ((session != null) && (session.isOpen())) {
session.close();
}
} catch (Exception e) {
Logger.write(LoggerConstant.CRITICAL_ERROR, e.getMessage(), e, methodName);
}
}
Apart from what ex0du5 has suggested, the exception trace also suggest following:
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)
Also there is a way where in you can monitor all the parameters (including max connection setting) of C3P0 conenction pool.