I am getting Cannot get a connection, pool error Timeout waiting for idle object, When I try to create more than 250 threads in my web application

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Connection Pool Exception: Cannot get a connection, pool error Timeout waiting for idle object

I am getting Cannot get a connection, pool error Timeout waiting for idle object error, When I try to create more than 250 threads in my web application. I am creating web application using JSF 2.0 and Hibernate.

I have tried with modified hibernate.xml,server.xml,context.xml and also mysql properties.

The followings are I am getting.

WARN (JDBCExceptionReporter.java:233) - SQL Error: 0, SQLState: null
ERROR (JDBCExceptionReporter.java:234) - Cannot get a connection, pool error Timeout waiting for idle object
ERROR (BaseServlet.java:301) - ******** java.lang.Thread.getStackTrace(Thread.java:1426)
    Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection
    org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
    org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
    org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
    org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
    sun.reflect.GeneratedMethodAccessor378.invoke(Unknown Source)
    Caused by: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot get a connection, pool error Timeout waiting for idle object
    org.apache.tomcat.dbcp.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:114)
    org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
    org.hibernate.connection.DatasourceConnectionProvider.getConnection(DatasourceConnectionProvider.java:92)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
    org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
    org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
    sun.reflect.GeneratedMethodAccessor378.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
    org.apache.tomcat.dbcp.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1144)
    org.apache.tomcat.dbcp.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:106)
    org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
    org.hibernate.connection.DatasourceConnectionProvider.getConnection(DatasourceConnectionProvider.java:92)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
    org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
    org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
    sun.reflect.GeneratedMethodAccessor378.invoke(Unknown Source)

Please if have any idea about this help me......

Harmeet Singh · Accepted Answer · 2012-07-31T09:58:37.490

6

Maybe you have set a timeout for "dead" connections and some queries take longer than that. That means that your pool removed a busy connection as "dead" from the pool and requests another from the DB - until the DB pulls the plug.

To debug this, enable logging for your connection pool, so you can see when it requests new connections.

also check your mysql connection settings. and try to close connection when you are done with your db coz next time(beyond maxConnectionAge limit) that connection state will be dead .

edited Jul 31 '12 at 09:58

answered Jul 31 '12 at 07:23

Harmeet Singh

2,555
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21

hi harmeet thanks for your response. – Ganesa Vijayakumar Jul 31 '12 at 11:30
Hi Thanks my problem fixed by changes in context.xml file I have changed followings properties in context.xml.file maxActive="-1" maxIdle="-1" maxWait="-1" -1 means NO Limit. – Ganesa Vijayakumar Aug 02 '12 at 14:48
1

@Ganesh please post your answer, if you have solved it yourself ortherwise mark as accepted whichever answer helped you. good luck :) – Harmeet Singh Aug 02 '12 at 14:50
@Ganesh one thing you should not do this, it will make your connections sleep, as i have suggested open connection work close connection – Harmeet Singh Aug 02 '12 at 14:53
This issues was happening by a protocol time delay. I debugged and solved that protocol issues after that i am not getting that exception. – Ganesa Vijayakumar Aug 02 '12 at 14:53
The connections are open and close as u said. – Ganesa Vijayakumar Aug 02 '12 at 15:00
@Ganesh set xml values to default there is no need to do that.if u are open and closing connection properly.. – Harmeet Singh Aug 02 '12 at 15:59

score 4 · Answer 2 · answered Jul 31 '12 at 07:18

I had such issue before, what you need to do is
close hibernate sessions when you are done with it.

e.g.

Session sess = factory.openSession();
 Transaction tx;
 try {
     tx = sess.beginTransaction();
     //do some work
     ...
     tx.commit();
 }
 catch (Exception e) {
     if (tx!=null) tx.rollback();
     throw e;
 }
 finally {
     sess.close(); // closing session
 }

I am getting Cannot get a connection, pool error Timeout waiting for idle object, When I try to create more than 250 threads in my web application

2 Answers2

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