Spring+hibernate数据源，多用户并发...

20个用户并发没有问题，50个的话服务器就会出现下面的报错信息：

<2010-9-7 上午11时13分17秒 CST> <Error> <HTTP> <BEA-101020> <[weblogic.servlet.i

nternal.WebAppServletContext@1f61bcf - appName: 'webroot', name: 'webroot', cont

ext-path: '/ses'] Servlet failed with Exception

org.springframework.transaction.CannotCreateTransactionException: Could not open

 Hibernate Session for transaction; nested exception is org.hibernate.exception.

GenericJDBCException: Cannot open connection

        at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegi

n(HibernateTransactionManager.java:538)

        at org.springframework.transaction.support.AbstractPlatformTransactionMa

nager.getTransaction(AbstractPlatformTransactionManager.java:350)

        at org.springframework.transaction.interceptor.TransactionAspectSupport.

createTransactionIfNecessary(TransactionAspectSupport.java:262)

        at org.springframework.transaction.interceptor.TransactionInterceptor.in

voke(TransactionInterceptor.java:102)

        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(

ReflectiveMethodInvocation.java:166)

        Truncated. see log file for complete stacktrace

org.hibernate.exception.GenericJDBCException: Cannot open connection

        at org.hibernate.exception.SQLStateConverter.handledNonSpecificException

(SQLStateConverter.java:91)

        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.j

ava:79)

        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelp

er.java:43)

        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelp

er.java:29)

        at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager

.java:363)

        Truncated. see log file for complete stacktrace

java.sql.SQLException: We are already in the process of making 11 connections an

d the number of simultaneous builds has been throttled to 10

        at org.logicalcobwebs.proxool.Prototyper.checkSimultaneousBuildThrottle(

Prototyper.java:260)

        at org.logicalcobwebs.proxool.ConnectionPool.getConnection(ConnectionPoo

l.java:170)

        at org.logicalcobwebs.proxool.ProxoolDataSource.getConnection(ProxoolDat

aSource.java:97)

        at org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource.

getConnection(AbstractRoutingDataSource.java:133)

        at com.dongyun.ses.web.DynamicDataSource.getConnection(DynamicDataSource

.java:57)

        Truncated. see log file for complete stacktrace>

希望大虾指点指点！