[Systems] pointing activities.sugarlabs.org at the proxy

[Bernie Innocenti]

El lun, 16-11-2009 a las 23:32 -0600, David Farning escribió:

> Yes, these are the pieces that I am trying to working out:
> -The entire data base was about 70 GB when I took the snapshot last week.

Err.. 70MB, not 70GB.

The entire mysql tablespace on sunjammer, comprising all databases, is
788MB.



> -The database uses both innobd and myisam tables.  All of the
> literature suggests that you don't mix table types unless you know
> what you are doing.... because, while it can be more effective, it
> make things hard to tune. 

Yeah, and now I also know the specific details: over the week-end I've
been digging through Drizzle's storage back-end API :-)


>   aslo-db currently has 4GB assigned, I will
> need to figure out how to best allocate that.

I think it's still an order of magnitude too much. In order to tune
these parameters, the best approach is to let the application run for a
while with small (default) caches and then collect runtime stats about
what caches were churning too much.

phpMyAdmin offers a *great* statistics dashboard with plenty of good
advice. It's the only feature I'd use it for.


> -Memcache is living on aslo-web. I have it set for .5GB  with 2.5GB
> available for the the apache and php processes.  I have bumped the
> time to store page in memcache from 60 seconds to 300 seconds.  This
> increased the memcache hit rate from mid 70% to mid 90%.

Ok.


> -Bernie was correct in his assumption of Squid.  The static files that
> I have been worried about are generally cached locally in the browser.
>  On the other hand, with running squid in front of the php server for
> siege benchmarks there seems to be about a 10% to 15% increase in
> transactions per second.

Perhaps the Mozilla people could give us an indication of how they
configured Squid.


> -My best result so far is 24 transactions per second.  I had to let it
> run for 6 hours undisturbed to completely warm the caches (I haven't
> been able to reproduce it)  Sunjammer maxed out at 13 transactions per
> second.

Do you know what's causing this 2x increase in throughput? On what
page(s) was it?


> > Ok then, I'll see if I could do it on the fly.
> 
> Berne, can you try to move the machine to partitions on lvm?

I tried, it's not as easy as I thought. I'd need a package called
guestfs-tools, which is not yet available for Ubuntu and has some weird
dependencies such as ocaml.

I'll do it this week-end from within the virtual machines, but it will
require restarting them twice.

We don't have to wait until I'm done before switching
activities.sugarlabs.org to production. If we're ready, I'll switch the
DNS tonight.


> I think the setup is getting close to useable.  But I am still
> concerned that the load average goes up before we max out the cpus.
> Is this a vm related issuse?

Yeah, this is really weird, I can't make sense of it. It may be
interference from the other XEN domains sharing the physical machine
(cloud9).

The load on that box should go down soon, when 2 new machines I'm
setting up for the FSF will transition into production.


>   The interrupts at
> http://sunjammer.sugarlabs.org/munin/sugarlabs.org/aslo-db.sugarlabs.org-irqstats.html
> look pretty high.

Hmm... I can't check now because I'm riding the T. If it's less than
1000 IRQs per second, then it's fine.

I'll investigate with powertop, which has the nice side-effect of
telling you what process is causing more interrupts.

-- 
   // Bernie Innocenti - http://codewiz.org/
 \X/  Sugar Labs       - http://sugarlabs.org/