Thx. A validationQuery is not required by DBCP, but if you pass an empty string it throws an exception.
Tomcat's admin app for JNDI DataSources creates a Validation Query with an empty string if no query is supplied, causing DBCP to throw an exception when invoked. In your opinion, is this a mistake by the Admin app for creating a empty string parameter, or a mistake by DBCP in handling an empty string? - Andrew > -----Original Message----- > From: Craig R. McClanahan [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, August 28, 2002 12:48 PM > To: Tomcat Users List > Subject: RE: tomcat conn pooling question > > > > > On Wed, 28 Aug 2002, Andrew Conrad wrote: > > > Date: Wed, 28 Aug 2002 12:34:03 -0400 > > From: Andrew Conrad <[EMAIL PROTECTED]> > > Reply-To: Tomcat Users List <[EMAIL PROTECTED]> > > To: 'Tomcat Users List' <[EMAIL PROTECTED]> > > Subject: RE: tomcat conn pooling question > > > > 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? > > > > It's inside commons-dbcp. Tomcat doesn't "run" anything -- > it just passes the configuration properties on to > BasicDataSourceFactory and lets commons-dbcp do its thing. > > Craig > > > > > > > - 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] > > > > > > > > > > > > -- > > > > To unsubscribe, e-mail: > > > <mailto:[EMAIL PROTECTED]> > > > For additional commands, e-mail: > > > <mailto:[EMAIL PROTECTED]> > > > > > > -- > > > To unsubscribe, e-mail: > > <mailto:[EMAIL PROTECTED]> > > > For additional commands, e-mail: > > > <mailto:[EMAIL PROTECTED]> > > > > > > > > > > > > -- > > To unsubscribe, e-mail: > > <mailto:[EMAIL PROTECTED]> > > For additional commands, e-mail: > > <mailto:[EMAIL PROTECTED]> > > > > > > -- > > To unsubscribe, e-mail: > <mailto:tomcat-user-> [EMAIL PROTECTED]> > > For > additional commands, > e-mail: > > <mailto:[EMAIL PROTECTED]> > > > > > > > -- > To unsubscribe, e-mail: > <mailto:tomcat-user-> [EMAIL PROTECTED]> > For > additional commands, > e-mail: <mailto:[EMAIL PROTECTED]> > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
