Craig, 

I'm troubleshooting a ValidationQuery issue, and I can't seem to find
where this query executes.

Does DBCP handle the ValidationQuery, or does Tomcat run the
ValidationQuery when the first connection is requested?



- Andrew

> -----Original Message-----
> From: Craig R. McClanahan [mailto:[EMAIL PROTECTED]] 
> Sent: Wednesday, August 28, 2002 12:25 PM
> To: Tomcat Users List
> Subject: RE: tomcat conn pooling question
> 
> 
> 
> 
> On Wed, 28 Aug 2002, Turner, John wrote:
> 
> > Date: Wed, 28 Aug 2002 09:51:29 -0400
> > From: "Turner, John" <[EMAIL PROTECTED]>
> > Reply-To: Tomcat Users List <[EMAIL PROTECTED]>
> > To: 'Tomcat Users List' <[EMAIL PROTECTED]>
> > Subject: RE: tomcat conn pooling question
> >
> >
> > When you say "Tomcat's connection pooling" what do you mean exactly?
> >
> > As far as I know, there is no connection pooling built-in to tomcat 
> > that actually works.
> 
> It does (at least in 4.1) if you set it up correctly :-).  
> The Tyrex stuff in 4.0 is problematic, which is one of the 
> reasons it got abandoned in 4.1.
> 
> >  The traffic I have seen on this list has people rolling their own, 
> > using open source pooling solutions like poolman or DBCP, 
> or using the 
> > pooling that comes from third-party driver vendors.  Which 
> one are you 
> > using?  That might give the list a better indicator of what's wrong.
> >
> 
> Note that Tomcat 4.1 uses commons-dbcp for its pooling.
> 
> In answer to Rick's original question, the standard 
> connection pool includes a "validationQuery" configuration 
> property.  This is an SQL query that the pool will execute 
> before it hands you back a requested connection (so it should 
> be something that executes very quickly).  If the connection 
> was closed externally (your scenario), this query will fail 
> and the pool will throw that connection away and give you 
> another one instead.
> 
> > John Turner
> > [EMAIL PROTECTED]
> 
> Craig
> 
> 
> >
> >
> > > -----Original Message-----
> > > From: Rick Reumann [mailto:[EMAIL PROTECTED]]
> > > Sent: Wednesday, August 28, 2002 9:37 AM
> > > To: Tomcat Users List
> > > Subject: tomcat conn pooling question
> > >
> > >
> > > Sorry if this is a repeat post. (I'm not sure if I posted this 
> > > question here or not as I was trying to switch from 
> digest mode to 
> > > regular list mode on this list and I ended up 
> unsubscribing from the 
> > > list so didn't get messages for a while).
> > >
> > > QUESTION:
> > >
> > > I've configured Tomcat's connection pooling according to Tomcat's 
> > > docs 
> http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jndi-resources

> > -howto.html
> > any everything seems to work fine unless someone manually kills the 
> > open connections (or something else causes the connections to go 
> > down). When the connections are manually killed the connection 
> > pooling ceases to work and the application breaks since it gets sql 
> > errors from the conn pool of
> > java.sql.SQLException: ORA-01012: not logged on
> >
> > Is there a way to make sure the connection pooling goes back to 
> > working if the app somehow has it's open connections killed? I 
> > thought adding  the validationQuery to the ResourceParams configured

> > in the server.xml file would help, but it doesn't.
> >
> > <parameter>
> >   <name>validationQuery</name>
> >    <value>SELECT 'CRAP' FROM DUAL</value>
> > </parameter>
> >
> > Thanks for any help.
> >
> > --
> >
> > Rick
> > mailto:[EMAIL PROTECTED]
> >
> >
> > --
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