Cannot get a connection, pool error Timeout waiting for idle object

[Elan Ram]

Hi

We are facing issue with dbcp connection pooling in combination of tomcat sever and MySQL. The summary of stack trace is:

   
[ERROR 2010-05-05 23:57:58,839] Sernks in avlet.service() for servlet action threw exception
org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; 
nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot get a connection, pool error Timeout waiting for idle object

Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot get a connection, pool error Timeout waiting for idle object

        at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:104)
        .......................................

Caused by: java.util.NoSuchElementException: Timeout waiting for idle object
        ... 35 more
 

when i googled, Adding "autoReconnect=true" with jdbc URL will help to solve our problem, making this change also not solving our problem.
Is there any other area that i need to concentrate to resolve the ussue?

[Sagar Rohankar]

How do you config your DBCP? Post the same xml here. You might set the maximum idle connection to very low count. Also are you releasing the connection properly ?

[Elan Ram]

Hi Sagar,

Thanks for your reply. Already we have very less max idle time. Here is the config:

    

<Context>




    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
	
        <Resource
                name="jdbc/someDS"
                auth="Container"
                type="javax.sql.DataSource"
                driverClassName="com.mysql.jdbc.Driver"
                factory="org.apache.commons.dbcp.BasicDataSourceFactory"
                url="jdbc:mysql://ipAddress/dbName"
                username="userName"
                password="password"
                autoReconnect="true"
				maxActive="300"
				maxWait="10000"
				removeAbandoned="true"
				logAbandoned="true"
				removeAbandonedTimeout="60"
				maxIdle="10"
				validationQuery="select 1"
        />
</Context>

Is there any issue with the configuration?

[Sagar Rohankar]

The config file looks OK to me, though your are setting max active to 300, in practice its not required that high. Also

url="jdbc:mysql://ipAddress/dbName?autoConnect=true"  

There is no point in passing the wrong command "autoConnect"

I strongly feel that, you are not properly closing the connection. Also as you are logging the abandoned connection, have you seen some exception for the same in log file?

[Sagar Rohankar]

Also, have look at DBCP page for some extra config you want to try out:
http://commons.apache.org/dbcp/configuration.html

[Elan Ram]

Hi,

We are using the internal framework for database operations so it might have tested properly. Even if it is poorly written we have configured as

   
removeAbandoned="true"  
 

so this will take care of it. At this moment I could not find the way to proceed.

Anyway thanks for your help.

[Sagar Rohankar]

Elan Ram wrote:We are using the internal framework for database operations

So you must specify that internal framework. Also ping the moderator to requesting to move this thread to JDBC section.