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Asked: 2026-06-12T09:15:05+00:00

I’m using oracle.ucp.jdbc.PoolDataSource for getting connections. Each connection wrapped to custom class (historic solution).

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I’m using

oracle.ucp.jdbc.PoolDataSource

for getting connections. Each connection wrapped to custom class (historic solution). Generally connection is getting by entityManager. My system require hight performance processing. There is ThreadPool using for it. Thread pool can provide 15 threads at the same time, like connection pool.
Every thing works fine, but sometimes i get exception (in this moment were used only 4 connections):

2012-09-26 17:51:45.835 | ERROR | ThreadExecutor-7 | org.hibernate.ejb.AbstractEntityManagerImpl | Exception in thread "ThreadExecutor-7"
javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1235)
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1168)
    at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:1245)
    at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:63)
    ...
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:619)
Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection
    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
    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:1463)
    at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:60)
    ...
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)

If i synchronize specified getConnection performance of the system going down 8-12 times.

Is any ideas for fix?

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1 Answer

  1. Editorial Team

    Please check you are setting appropriate values for 

     <property name="minPoolSize" value="5"/>
 <property name="maxPoolSize" value="100"/>//Change if you want
 <property name="initialPoolSize" value="5"/>
 <property name="validateConnectionOnBorrow" value="true"/>
 <property name="maxStatements" value="10"/>

    You can check configuration here

    You should change connection pooling in hibernate.

    http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/session-configuration.html

    Hibernate’s own connection pooling algorithm is, however, quite rudimentary. It is intended to help you get started and is not intended for use in a production system, or even for performance testing. You should use a third party pool for best performance and stability. Just replace the hibernate.connection.pool_size property with connection pool specific settings. This will turn off Hibernate’s internal pool. For example, you might like to use c3p0. 

    hibernate.c3p0.min_size=5
hibernate.c3p0.max_size=20
hibernate.c3p0.timeout=1800
hibernate.c3p0.max_statements=50
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