On Thursday 06 November 2003 21:49, dhay@... wrote:

>
> I am stressing the database as hard as I can with JMeter

You're obviously not stressing it enough. :-)

> , and see the
> following:
>
> Page Buffer Memory Usage VM Size
> 2048 (8 MB) 9 - 11 MB 14 MB
> 10000 (39 MB) 11 - 12.5 MB 47 MB
> 20000 (78 MB) 13 - 15 MB 89 MB
>
> Is this normal?
>

More or less. Firebird 1.0 is compiled to allow the operating system to page
all memory out to virtual disk. This is (or was) MS's recommendation for
correct behaviour. It seems daft to me - because every read from disc to
cache seems to be paged out to disc again.

I don't recall whether this has been changed for Fb 1.5.

That aside, the O/S then handles the allocation of real memory and it looks
as if the O/S thinks that approx 10Mb is all you/Firebird need.

I know this question may sound blindingly obvious, but I have to ask it - Is
your test database big enough and is JMeter doing enough to ask queries
that will load large tables? The O/S will release memory to the application
if the application needs it but it looks as if Firebird doesn't.


Paul
--
Paul Reeves
http://www.ibphoenix.com
Supporting users of Firebird and InterBase