RE: [Proxool-developer] Re: Proxool and web apps

[Martin C. <mus...@us...>]

> We added a ReloadMonitor in 0.5 that should fix that. As soon as Proxool
> is reloaded then it closes all the old connection pools. Can you try out
> 0.5 and let us know if it fixes it?

Ah, now I have a reason for 0.5, guess I'm using your patched version for
jxDbCon;)

Although, I tried it out and a) the following exception dump was thrown to
the Tomcat stdout, and b) I eventually ran out of connections to my
database. So I guess it didn't really fix it. Tomcat version is latest
stable 4.1.12.

Dec 11, 2002 3:35:25 PM org.logicalcobwebs.proxool.ConnectionPool finalize
INFO: Closing down instance started at Wed Dec 11 15:33:55 EST 2002 -
waiting for 500 milliseconds for everything to stop.
[ReloadMonitor.proxool:org.sourceforge.jxdbcon.JXDBConDriver:jdbc:postgresql
:net//username:password@localhost:4321/database]
WebappClassLoader: Lifecycle error : CL stopped

Dec 11, 2002 3:35:25 PM org.logicalcobwebs.proxool.ConnectionPool finalize
SEVERE: Unknown problem finalizing pool
java.lang.NoClassDefFoundError: java/lang/Math
        at
org.logicalcobwebs.proxool.ConnectionPool.finalize(ConnectionPool.java:482)
        at
org.logicalcobwebs.proxool.ProxoolFacade.removeConnectionPool(ProxoolFacade.
java:295)
        at
org.logicalcobwebs.proxool.ProxoolFacade.removeAllConnectionPools(ProxoolFac
ade.java:330)
        at
org.logicalcobwebs.proxool.ReloadMonitor.isProxoolReloaded(ReloadMonitor.jav
a:79)
        at
org.logicalcobwebs.proxool.ConnectionPool$HouseKeeper.run(ConnectionPool.jav
a:608)
        at java.lang.Thread.run(Thread.java:536)

I guess I'll go back to deploying to the commons classpath. In reality, this
is the "proper" place for such a thing. It is usually recommended that JDBC
drivers are deployed to the "common" folder as they should be usable across
applications. Additionally, it would make more sense to put your connection
pool higher up so the same apps that potentially use the sames resources can
benefit from shared resources. But this is now philosophical if the
ReloadMontior works.

> Sometimes when a database is down it is nice to see Proxool
> automatically pick up the connections when it comes back up again
> though. I suppose this should be a configurable nice-to-have.

I agree it's nice to have, but if the URL was never right to begin with it's
like kicking a dead horse.

> It shouldn't actually be a very intensive background process. By
> default, the house keeping thread runs every 30 seconds and if it fails
> to make the first spare connection it gives up on the rest. So the only
> process activity is to attempt to build a connection once every 30
> seconds. And if the database is down then this activity is less than you
> would normally experience.

Even through it's a small process, every bit of memory helps. I will add
this as a feature to the tracker, but I agree it isn't the most critical
thing in the world.

Martin