CentOS - Oct 2008 - Possibly OT: intermittently long response times, when connecting to host

Craig White <craigwhite at azapple.com> wrote:
> On Tue, 2008-10-28 at 16:30 -0500, David Miller wrote:
>   
>> > I have a CentOS 5.2 server running Apache 2.2.3 (yum installed)
and
>> > drupal 6.5 on ESX 3.5. We're using Name Based Virtual Hosting
on it -
>> > 2 hosts. The problem is that when I pull up a web page after not
>> > having accessed it for ~15+ minutes it takes between 10-12s to
load
>> > fully. The 2nd page, 3rd page - and sometimes more than that -
take
>> > between 8-12 second. After that - decent performance, though not
great
>> > (0.3s to 2s). Wait ~15 minutes, maybe more, maybe less, and it
goes
>> > back to slow. While it's been most apparent with httpd,
I've noticed
>> > similar slowness with the initial ssh session, etc.
>> > 
<snip>
> ----
> sounds sleepy - perhaps the mysql connections drop after inactivity and
> then it takes that long to connect
>
> You might just want to set up a cron script that does a curl or wget of
> a standard page every 2 minutes or so just to keep things active.
>   
I'm working with some folks to develop a web site with a very similar 
configuration (Apache, Drupal, MySQL, not sure which Linux distro is 
underneath it all though) that's hosted by IX web hosting.  We are 
seeing very similar behavior.  It has gotten better since we complained 
to IX but we still see a significant lag the first time the site loads.  
The fast load on subsequent visits could be explained by Drupal doing 
some caching of needed items so it doesn't have to go to the database.

The initial site load time became much more noticeable after IX took 
some kind of hit on their DB server.  All we know is the site suddenly 
couldn't connect to the database, they fixed something on their end and 
the database came back but we've had the long lag for first load ever since.

BTW, pleased to make your acquaintance, Dave.

Cheers,
Dave Miller

-- 
Politics, n. Strife of interests masquerading as a contest of principles.
-- Ambrose Bierce

--snip--
>
> I'm working with some folks to develop a web site with a very similar
> configuration (Apache, Drupal, MySQL, not sure which Linux distro is
> underneath it all though) that's hosted by IX web hosting.  We are
seeing
> very similar behavior.  It has gotten better since we complained to IX but
> we still see a significant lag the first time the site loads.  The fast
load
> on subsequent visits could be explained by Drupal doing some caching of
> needed items so it doesn't have to go to the database.
>
> The initial site load time became much more noticeable after IX took some
> kind of hit on their DB server.  All we know is the site suddenly
couldn't
> connect to the database, they fixed something on their end and the database
> came back but we've had the long lag for first load ever since.
>
> BTW, pleased to make your acquaintance, Dave.
>
> Cheers,
> Dave Miller
>
> --
> Politics, n. Strife of interests masquerading as a contest of principles.
> -- Ambrose Bierce
>
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>
We were thinking along similar lines and turned off caching. We also
added the drupal 'devel' module. It can be set up to show all the DB
calls a page is making. So far some slow queries, but nowhere near
explaining the whole 10-12s.

So far I've been able to rule out apache, php rendering, and DNS. It's
almost definitely a MySQL connection issue, and I'm reasonably certain
it's a php-mysql issue. Interestingly we've copied over the drupal
install to Fedora 8 and Fedora 9 boxes and it runs like a champ. I've
got a basic Drupal 6.5 install on my desktop (CentOS 5.2 x86_64) and
it runs well. I'm in the process of installing CentOS 5.2 on another
ESX VM to see if "something" was installed wrong, etc. Not ruling out
operator error here.

Nice to meet you as well, Dave. There certainly are a few of us
floating around.

Thanks.
David M Miller