Re: [Proxool-developer] Connection release latency when using proxool with PostgreSQL

[Bill H. <bi...@lo...>]

Hi Jean,

On Thu, 2003-12-11 at 00:16, Jean-Henry Berevoescu wrote:

> The traces are not showing anything unusual, but I noticed another
> thing:
> - I start with minumumConnectionCount set to, say, 30. Proxool is
> correctly
> building 30, but the first time I need a connection it builds another
> one, and
> another one and so on, every time a need a connection from the pool.
> So it looks like the reusability is not working.
> Again, it was working all right with Informix, but not with
> PostgreSQL.

I'd like to see more of the log to find out what's going on there. It
should show those initial 30 connections being built. And then it will
show what happens when you ask for your first connection to use. We can
then see whether it is reusing one of those initial 30 or making a new
one.

> 987 [Prototyper] DEBUG org.logicalcobwebs.proxool.globexplorer_0  -
> org.postgresql.Driver does not support getHoldability. Proxool doesn't
> mind.
> 988 [Prototyper] DEBUG org.logicalcobwebs.proxool.globexplorer_0  -
> org.postgresql.Driver does not support setHoldability. Proxool doesn't
> mind.
[snip]
> What exactly "Holdability" means? I noticed I have it with Informix,
> but not here.

It's part of the JDBC API, but not all Drivers support it. Like the log
says, Proxool doesn't mind either way. You'll find that your Informix
driver does support it whilst your Postgresql one doesn't.

> Also, how one can programatically set the connection to be readOnly? I
> always use it as readOnly in what I try to do here and I noticed
> proxool is setting it to default = false.

Proxool is simply remembering the readOnly state of new connections. The
default state is false (that is, writable). That is how the connections
are supplied from the Postgresql Driver. Proxool resets all these states
to their original values when you return a connection to the pool.
Otherwise, if you changed something it would remain at that new value
when you asked for another connection and that might not be what you
want. So: every time you ask Proxool for a connection it comes in the
sames state as when it arrived, fresh from the Postgresql Driver.

Regards,
Bill Horsman