Auto-commit changes to TRUE after a while using a connection pool

Question

I got some strange problem.

I use a Pool to create and manage DB Connections, I set the DefaultAutocommit option to FALSE.

But after a while, when an error occur and a rollback is called an Exception is thrown : Can't call rollback when autocommit=true

Relaunching JBoss will solve the problem as a new DataSource will be created.

Here is how I create my Datasource :

protected DataSource getDataSource(String driverClassName, String dbUrl, String dbUser, String dbPwd) {
    PoolProperties poolProperties = new PoolProperties();
    poolProperties.setUrl(dbUrl);
    poolProperties.setDriverClassName(driverClassName);
    poolProperties.setUsername(dbUser);
    poolProperties.setPassword(dbPwd);

    poolProperties.setDefaultAutoCommit(false);
    poolProperties.setTestWhileIdle(false);
    poolProperties.setTestOnBorrow(true);
    poolProperties.setDefaultTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
    poolProperties.setValidationQuery("SELECT 1");
    poolProperties.setTestOnReturn(false);
    poolProperties.setLogAbandoned(false);
    poolProperties.setRemoveAbandoned(true);
    poolProperties.setRemoveAbandonedTimeout(20);
    poolProperties.setMaxActive(100);
    poolProperties.setInitialSize(10);
    poolProperties.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");

    return new DataSource(poolProperties);
}

And how I get the connections :

xxx.getDataSource().getConnection();

I didn't try yet but my first call will be to force the autocommit directly on the connection using setAutoCommit(false).

Though I don't understand why the poolProperties.setDefaultAutoCommit(false); is stopping doing the job.

Stack trace :

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Can't call rollback when autocommit=true
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    at com.mysql.jdbc.Util.getInstance(Util.java:384)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:929)
    at com.mysql.jdbc.ConnectionImpl.rollback(ConnectionImpl.java:4805)
    at sun.reflect.GeneratedMethodAccessor302.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:125)
    at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:94)
    at org.apache.tomcat.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:71)
    at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:94)
    at org.apache.tomcat.jdbc.pool.interceptor.ConnectionState.invoke(ConnectionState.java:140)
    at $Proxy333.rollback(Unknown Source)

Answer 1

So here is what is in place today, I force the AutoCommit attribute on each connection created by the pool.

This works, so it definitely may be a bug of the pool classes.

Edit: I also had a problem with transaction isolation that was set the same way but not taken into account. After some research I found that this could be related to the Mysql connector/J I use (http://dev.mysql.com/doc/refman/5.1/en/connector-j-reference-configuration-properties.html) .

I found this interesting parameter in the doc :

useLocalSessionState

Should the driver refer to the internal values of autocommit and transaction isolation that are set by Connection.setAutoCommit() and Connection.setTransactionIsolation() and transaction state as maintained by the protocol, rather than querying the database or blindly sending commands to the database for commit() or rollback() method calls?

Default value : false