RE: JBoss keeps sending select 'hello' from dual

From: <>
Date: Tue, 28 Oct 2008 15:17:04 -0400
Message-ID: <>

Well, what we tried was swapping out  

<check-valid-connection-sql >select 'hello' from dual </check-valid-connection-sql >
<!--valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc. vendor.OracleValidConnectionChecker</valid-connection-checker-class-name

However that seems to generate an equal number of  

select 'x' from dual  

statements so I don't know that we've gained very much. Anyone have other suggestions?  

Jay Miller
Sr. Oracle DBA

From: Jared Still [] Sent: Thursday, October 23, 2008 6:10 PM To: Miller, Jay
Subject: Re: JBoss keeps sending select 'hello' from dual

Don't keep us in suspense like that.

What was it?

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

On Thu, Oct 23, 2008 at 1:47 PM, <> wrote:

        Never mind.         

        I tried some different search terms in Google after sending this out and

        think I've found the answer. Sorry about that.                  

        Jay Miller         

	-----Original Message-----
	[] On Behalf Of
	Sent: Thursday, October 23, 2008 4:34 PM
	Subject: JBoss keeps sending select 'hello' from dual
	While investigating some performance issues on two unrelated
	one of the odd things we found was a huge number of "select
'hello' from
	statements hitting the databases (as in over a million/hour).
	Further investigation leads us to believe that this is a
	feature of JBoss connection pooling and the method it uses to
check if a
	connection is still alive but we couldn't find any real details
on it.         

        Just wondering if anyone else has encountered this before and can point

        me to additional information or any way of reducing its impact.         

	Jay Miller

Received on Tue Oct 28 2008 - 14:17:04 CDT

Original text of this message