I'm evaluating jdbc pool after reading some blogs on tomcatexpert.com. But when I try to switch to jdbc pool from dbcp, I'm getting stackoverflow error like this: Caused by: java.lang.StackOverflowError at java.util.concurrent.AbstractExecutorService.<init>(AbstractExecutorService.java:71) at java.util.concurrent.ThreadPoolExecutor.<init>(ThreadPoolExecutor.java:1270) at java.util.concurrent.ThreadPoolExecutor.<init>(ThreadPoolExecutor.java:1163) at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:117) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:127) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:86) at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDataSource(PooledConnection.java:224) at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:180) at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:699) at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:631) at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:485) at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:127) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:86) at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDataSource(PooledConnection.java:224) at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:180) at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:699) at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:631) at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:485) at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:127) at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:86) at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDataSource(PooledConnection.java:224) and I noticed that someone had the same issue before but not answered: http://mail-archives.apache.org/mod_mbox/tomcat-users/201107.mbox/%3C32046311.post@talk.nabble.com%3E my web app is a typical springmvc+hibernate application, and here is my applicationcontext datasource part: <bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close"> <property name="driverClassName" value="${telregistry.jdbc.driverClassName}" /> <property name="url" value="${telregistry.jdbc.url}"/> <property name="username" value="${telregistry.jdbc.username}"/> <property name="password" value="${telregistry.jdbc.password}"/> <property name="initialSize" value="5"/> <property name="initSQL" value="SELECT 1"/> <property name="minIdle" value="5"/> <property name="maxIdle" value="50"/> <property name="maxActive" value="100"/> <property name="maxWait" value="6000"/> <property name="validationInterval" value="1800000"/> <property name="validationQuery" value="SELECT 1"/> </bean> my system: win7 32bit jdk1.7.0_9(also test on jdk1.6.0_25) mysql 5.5(also test oracle11g) spring 3.1.0 jdbc pool(tomcat-jdbc-7.0.30.jar from official maven repo) And by tomcat container resource configuration, I find a workaround to make jdbc pool work with spring: 1. add a Resource section in tomcat server.xml to make a global naming resource 2. add a resource-ref section in WEB-INF/web.xml to reference container resource 3. add a bean section to spring applicationContext.xml to reference container resouce by spring provided JndiObjectFacetoryBean
1. The call to ConnectionPool.borrowConnection( ) is caused by setting <property name="initialSize" value="5"/> which causes ConnectionPool.init() to create 5 connections. 2. The call to PooledConnection.connectUsingDataSource() is seriously wrong. It should have called PooledConnection.connectUsingDriver() instead. This can happen only if poolProperties.getDataSource() is not null. I do not see how this could have happened. Did Spring injected a recursive reference by calling DataSource.setDataSource()? 3. When you define the pool via <Resource>, it is created using org.apache.tomcat.jdbc.pool.DataSourceFactory. The factory calls dataSource.createPool(). So it might be better to add init-method="createPool".
Do you have autowire in Spring enabled? If so, it'll inject a 'dataSource'-object in the setDataSource-property of your DataSource-instance... Its a bit weird that the object has a setDataSource-method at all, but you can fairly easily fix it by setting autowire="no" on the particular pool, like so: <bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close" autowire="no">
This can only happen if you inject your datasource (the actual pool). So this must be a misconfiguration on the users part. Pool now prevents it through r1616595