Thanks, that's good to know, especially about the validationInterval setting. The idea of not validating every single time seems more reasonable.
-Alec On Tue, Dec 3, 2013 at 12:32 PM, Daniel Mikusa <dmik...@gopivotal.com>wrote: > On Dec 3, 2013, at 12:14 PM, Tomcat Random <tomcat.ran...@gmail.com> > wrote: > > > I considered using a validation query but it seemed like extra overhead > > when the default behavior was not, um, behaving in the default way. > > The overhead is typically minimal. Running "SELECT 1" or some other very > simply query is not likely to bring your database to it's knees. It might > add a small amount of latency as the pool will need to execute the query > before it give the connection to your application, but that's likely to be > dwarfed by whatever your application does with the connection after it gets > it. > > If you are concerned you can do a couple things to make the process even > more lightweight. > > 1.) With MySQL and use "/* ping */ SELECT 1" as the validation query. > This is a special case with the MySQL JDBC driver that uses even less > resources. > > 2.) You can use the tomcat-jdbc connection pool which has a > validationInterval setting. This will ensure that the validation query is > only executed one time during the specified time interval. > > ...or you can go without a validation query, but it's not something I > would recommend and not something I see done very often. The minimal > overhead is usually worth knowing that you get a valid connection from the > pool. > > Dan > > > > > On Tue, Dec 3, 2013 at 7:24 AM, Daniel Mikusa <dmik...@gopivotal.com> > wrote: > > > >> On Dec 2, 2013 10:09 PM, "Neven Cvetkovic" <neven.cvetko...@gmail.com> > >> wrote: > >>> > >>> On Dec 2, 2013 12:47 PM, "Tomcat Random" <tomcat.ran...@gmail.com> > >> wrote: > >>>> > >>>> Neven, thank you. > >>>> > >>>> It was right there in my.cnf: 'wait_timeout=600' > >>>> > >>> > >>> You're welcome :) > >>> > >>> I am curious why tomcat didn't renew expired (terminated) idle > >> connections > >>> though. > >> > >> It wouldn't know that the connections have been disconnected, since they > >> were disconnected server side. If the user added a validation query > then > >> it could detect and remove the closed connections. > >> > >> Dan > >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
