config as <idle-timeout-minutes>180</idle-timeout-minutes> then the question is solved the reason: in mysql,default global.wait_timeout is 28800 second,if the value of idle-timeout-minutes more than global.wait_timeout,and when mysql close the idle connection,the connection still in the jboss connection pool.then if jboss application get the connection from pool,however the connection in not exist. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4096829#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...