Thread: [Re] Need help with postgresql/apache/php optimisation

Thx for your quick answer too :)

Richard Huxton wrote:
>
> On Wednesday 18 February 2004 20:18, Froggy / Froggy Corp. wrote:
> > Hello,
> >
> >       I asked one time for more "benchmark" soft to know where is the cpu
> > average, and read the post about optimising the postgresql.conf (and use
> > them), but i allways get a load > 1 on fire time (dunno the right name,
> > "coup de feu" in french (10h00 -> 14h00, 18h00 -> 21h00).
>
> This is the period when you get the most hits, yes?

yes

> > With different software, i dont see anything wrong (or i dont understand
> > how to use them), the problem is the memory which make some nice road
> > around 12Mo Free and 3Mo Free, but the swap dont really grow up (but
> > linux make a lot of cache).
>
> Not sure I understand you fully, but if swap isn't active you should be OK.
> See below for a good test.

Swap is active, but the size don't change a lot. (12Mb common time,
maybe 50Mb on rush time).

> There are three things to look at while testing this:
> 1. The output of "vmstat 1" - this will show memory usage, swap activity disk
> blocks in/out, cpu usage etc.
> 2. The output from "top", press "M" to sort by memory usage - that way we can
> see how much memory is being used.
> 3. How many requests are you processing at the same time?

I will use vmstat 1 tomorrow (22:24 here, so too late)

Around 4/5 postgresql thread and around 20 apache thread with top.
With mod-status from apache, i get same information, 20 requests in
process, but only some in activity.

> > If someone could help me, i need to put a new feature which will add
> > more than 2000 hit per day and im afraid about the life of the server
>
> Only 5000 hits per day? I'm sure we can get that working.

I hope :D.

Another question, i put on postgresql.conf a limited number of
postgresql max_connections, and use permanent link beetween apache and
postgresql. The problem is that a lot of apache thread is used for
sending data (gfx). Is there a way to say that some thread are only here
for php process ?

thx in advance,
regards,

On Wed, 18 Feb 2004, Froggy / Froggy Corp. wrote:

> Another question, i put on postgresql.conf a limited number of
> postgresql max_connections, and use permanent link beetween apache and
> postgresql. The problem is that a lot of apache thread is used for
> sending data (gfx). Is there a way to say that some thread are only here
> for php process ?

No, PHP's "connection pooling" is more of an accident looking for a place
to happen than useful sometimes.  you might want to try reverting to just
plain pg_connects and see how the machine behaves.

In fact, under php4.?, the connexion is not save under session, so i
allways need to make a pg_connect. But under documentation it say that
the socket stay open, so i save some cpu.

"scott.marlowe" wrote:
>
> On Wed, 18 Feb 2004, Froggy / Froggy Corp. wrote:
>
> > Another question, i put on postgresql.conf a limited number of
> > postgresql max_connections, and use permanent link beetween apache and
> > postgresql. The problem is that a lot of apache thread is used for
> > sending data (gfx). Is there a way to say that some thread are only here
> > for php process ?
>
> No, PHP's "connection pooling" is more of an accident looking for a place
> to happen than useful sometimes.  you might want to try reverting to just
> plain pg_connects and see how the machine behaves.

On Wednesday 18 February 2004 21:35, Froggy / Froggy Corp. wrote:
>
> Another question, i put on postgresql.conf a limited number of
> postgresql max_connections, and use permanent link beetween apache and
> postgresql. The problem is that a lot of apache thread is used for
> sending data (gfx). Is there a way to say that some thread are only here
> for php process ?

Given your lack of memory, I'd drop the permanent (persistent) connections
between php and postgresql - connect for every page you need to. That should
free up some memory.

Once we have the vmstat figures, we can look at how to tune postgresql.conf
--
  Richard Huxton
  Archonet Ltd

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