Re: Total crash of my db-server

Hi Justin,

average load is usually somewhat around 0.5,
at higher load there is sometimes even 3.0 or up to 7.0

it's a dedicated postgresql-machine. all accesses are made
by a webserver in the same subnet. There are about 15.000
daily users. Each request to the webserver triggers one or
more accesses to the database (using persistent connections,
mod_perl, squid as a proxy, etc.)

The webserver is set to MaxClients == 40 ... this limit has
as far as I can say never been reached before. So there should
never be more than 40 concurrent postgresql-processes.

When dumpall or reindexing / vacuum full is run at nights,
the webserver is shut down first.

disk benchmarking programs would perhaps be interesting
(which one do you suggest?)... but note: it's a production
server, and I have had allready too much downtime this
month...

--

Mit freundlichem Gruß

Henrik Steffen
Geschäftsführer

top concepts Internetmarketing GmbH
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----- Original Message -----
From: "Justin Clift" <justin(at)postgresql(dot)org>
To: "Henrik Steffen" <steffen(at)city-map(dot)de>
Cc: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>; <pgsql-general(at)postgresql(dot)org>
Sent: Monday, December 16, 2002 1:59 PM
Subject: Re: [GENERAL] Total crash of my db-server

> Henrik Steffen wrote:
> > hi tom,
> >
> > ok, I understand this.
> >
> > But: There is ONLY postgres running on this particular
> > machine. And it's mostly when backup (dumpall) and/or
> > vacuuming/reindexing is going on.
> >
> > In my opinion, postgresql does something on my machine
> > that leads to these complete system lockups.
>
> It sounds like the system lockups are occuring perhaps due to disk I/O,
with PostgreSQL being the program causing the
> disk load past what the system handles.
>
> How much load does this system normally have, when there aren't
dumps/vacuums/reindexes going on? Trying to understand
> how much load your system normally copes with before locking up.
>
> ?
>
> As a thought, if this is really being caused by disk I/O loads, then it
might be able to trigger it on demand with disk
> benchmarking programs (just an idle thought). That could be useful to
know about.
>
> Regards and best wishes,
>
> Justin Clift
>
> --
> "My grandfather once told me that there are two kinds of people: those
> who work and those who take the credit. He told me to try to be in the
> first group; there was less competition there."
> - Indira Gandhi
>