[Zope-dev] SWAP issue

Toby Dickenson tdickenson@geminidataloggers.com
Thu, 5 Sep 2002 14:41:08 +0100


On Thursday 05 Sep 2002 2:58 am, Ahsan Imam wrote:
> Hello All,
>
> I am currently running zope 2.5 and python 2.1.3.=20

Are you actually seeing the zope processes use too much memory?

2.5.x have a ZODB cache mechanism that does not respond well to memory=20
pressure. If your application touches many objects per transaction then=20
memory usage may grow out of control. 2.6 improves this significantly.

> The machine has 2 gigs of
> rams and is running on Red Hat 7.2.

Which kernel?

> After starting zope eveything works fine for a while. Slowly the swap
> starts to swell up

Memory that is not being actively used might as well be moved into swap,=20
freeing the ram for more productive uses. This does not necessarily indic=
ate=20
a problem.

> and after a few hours the machine has to be rebooted.
> The funny thing is that free shows that there is almost a gig of RAM fr=
ee
> and swap keeps on growing.=20

Are you sure you are interpreting the output from 'free' correctly? It is=
=20
often misinterpreted. (please post the output from 'free -m' if you are n=
ot=20
sure.)

> After a while the machine simply hangs.

> I have recompiled python and zope. Turned on profiling.
> I have looked through the stupid.log. There are no core dumps either. I
> have also tried running zope with one thread.
>
> Does anyone have suggestions.

you havent explained why you think this is a zope problem.