Commons Dbcp
  1. Commons Dbcp
  2. DBCP-400

The documentation of maxOpenPreparedStatements parameter seems to be wrong

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 1.4, 1.4.1
    • Fix Version/s: 1.5.1, 2.0
    • Labels:

      Description

      We had earlier a datasource, which had no maxOpenPreparedStatements property defined. Something like this:

      <bean id="basicDataSource" class="org.apache.commons.dbcp.BasicDataSource" init-method="createDataSource" destroy-method="close">
      		<property name="poolPreparedStatements" value="true" />
      		<property name="url" value="${datasource.url}" />
      		<property name="driverClassName" value="${datasource.driverClassName}" />
      		<property name="username" value="${datasource.username}" />
      		<property name="password" value="${datasource.password}" />
      
      		<property name="initialSize" value="${datasource.initialSize}" />
      		<property name="maxActive" value="${datasource.maxActive}" />
      		<property name="maxIdle" value="${datasource.maxIdle}" />
      		<property name="minIdle" value="${datasource.minIdle}" />
      
      		<property name="timeBetweenEvictionRunsMillis" value="${datasource.timeBetweenEvictionRunsMillis}" />
      		<property name="minEvictableIdleTimeMillis" value="${datasource.minEvictableIdleTimeMillis}" />
      		<property name="maxWait" value="${datasource.maxWait}" />
      	</bean>
      

      Then we wanted to have a parameter to limit the prepared statement pool, so we added a new line for the maxOpenPreparedStatements (for compatibility reasons we added the line with a config file having '0' value which should mean unlimited according to the documentation at http://commons.apache.org/proper/commons-dbcp/configuration.html):

      <bean id="basicDataSource" class="org.apache.commons.dbcp.BasicDataSource" init-method="createDataSource" destroy-method="close">
      		<property name="poolPreparedStatements" value="true" />
      		<property name="maxOpenPreparedStatements" value="${datasource.maxOpenPreparedStatements}" />		
      		<property name="url" value="${datasource.url}" />
      		<property name="driverClassName" value="${datasource.driverClassName}" />
      		<property name="username" value="${datasource.username}" />
      		<property name="password" value="${datasource.password}" />
      
      		<property name="initialSize" value="${datasource.initialSize}" />
      		<property name="maxActive" value="${datasource.maxActive}" />
      		<property name="maxIdle" value="${datasource.maxIdle}" />
      		<property name="minIdle" value="${datasource.minIdle}" />
      
      		<property name="timeBetweenEvictionRunsMillis" value="${datasource.timeBetweenEvictionRunsMillis}" />
      		<property name="minEvictableIdleTimeMillis" value="${datasource.minEvictableIdleTimeMillis}" />
      		<property name="maxWait" value="${datasource.maxWait}" />
      	</bean>
      

      We ended up in having the following exception:

      Caused by: java.sql.SQLException: MaxOpenPreparedStatements limit reached
      	at org.apache.commons.dbcp.PoolingConnection.prepareStatement(PoolingConnection.java:109)
      	at org.apache.commons.dbcp.DelegatingConnection.prepareStatement(DelegatingConnection.java:281)
      	at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.prepareStatement(PoolingDataSource.java:313)
      	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      ...
      ...
      [:1.7.0_07]
      	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)[:1.7.0_07]
      	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.7.0_07]
      	at java.lang.reflect.Method.invoke(Method.java:601)[:1.7.0_07]
      	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
      	at org.springframework.osgi.service.importer.support.internal.aop.ServiceInvoker.doInvoke(ServiceInvoker.java:58)
      	at org.springframework.osgi.service.importer.support.internal.aop.ServiceInvoker.invoke(ServiceInvoker.java:62)
      	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
      	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
      	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
      	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
      	at org.springframework.osgi.service.util.internal.aop.ServiceTCCLInterceptor$1.run(ServiceTCCLInterceptor.java:47)
      	at org.springframework.osgi.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:124)[80:org.springframework.osgi.core:1.2.1]
      	at org.springframework.osgi.service.util.internal.aop.ServiceTCCLInterceptor.invokePrivileged(ServiceTCCLInterceptor.java:44)
      	at org.springframework.osgi.service.util.internal.aop.ServiceTCCLInterceptor.invoke(ServiceTCCLInterceptor.java:36)
      	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
      	at org.springframework.osgi.service.importer.support.LocalBundleContextAdvice.invoke(LocalBundleContextAdvice.java:59)
      	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
      	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
      	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
      	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
      	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
      	at $Proxy69.getSpecializedSequenceProvider(Unknown Source)
      	at ...)
      	... 36 more
      Caused by: java.util.NoSuchElementException: Pool exhausted
      	at org.apache.commons.pool.impl.GenericKeyedObjectPool.borrowObject(GenericKeyedObjectPool.java:1143)
      	at org.apache.commons.dbcp.PoolingConnection.prepareStatement(PoolingConnection.java:107)
      	... 67 more
      

      So it turned out, that the documentation is wrong. Only negative numbers like -1 mean unlimited. 0 seems to mean limited to one item. Please correct the documentation to avoid problems of others.

        Activity

        Gábor Lipták created issue -
        Mark Thomas made changes -
        Field Original Value New Value
        Status Open [ 1 ] Resolved [ 5 ]
        Fix Version/s 1.5.1 [ 12325670 ]
        Fix Version/s 2.0 [ 12313721 ]
        Resolution Fixed [ 1 ]
        Phil Steitz made changes -
        Status Resolved [ 5 ] Closed [ 6 ]

          People

          • Assignee:
            Unassigned
            Reporter:
            Gábor Lipták
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            Dates

            • Created:
              Updated:
              Resolved:

              Development