unicorn Ruby/Rack server user+dev discussion/patches/pulls/bugs/help
 help / color / mirror / code / Atom feed
From: Clifton King <cliftonk@gmail.com>
To: unicorn list <mongrel-unicorn@rubyforge.org>
Cc: unicorn list <mongrel-unicorn@rubyforge.org>,
	Lawrence Pit <lawrence.pit@gmail.com>
Subject: Re: workers not utilizing multiple CPUs
Date: Tue, 31 May 2011 09:07:01 -0500	[thread overview]
Message-ID: <7E16F5B9-2C96-426F-BC75-670BEDD122A9@gmail.com> (raw)
In-Reply-To: <BANLkTinX0t35a7Mu1vk=DwxwO6EZj-gptA@mail.gmail.com>

We experience the same problem. I believe the problem has more to do with the kernel CPU scheduler than anything else. If you figure put a reliable way to spread the load, I'd like to hear it. 

Clifton King
Development
clifton@orgsync.com
512-940-7744

Sent from my phone. 

On May 31, 2011, at 7:20 AM, Nate Clark <nate@pivotallabs.com> wrote:

> Lawrence,
> 
> I've suspected that it may be a monitoring problem and not a Unicorn
> problem, but I'm not yet convinced either way. Our monitoring via
> collectd is done through Rightscale. They have a lot of experience
> with EC2, so I'd assume that it is monitoring properly. Also, our
> other services (mysql, for example) are showing activity on multiple
> cores under load, so that leads me to believe that the monitoring is
> working in at least some cases.
> 
> I wasn't aware of the Cloudwatch service until now, that looks
> interesting ... I'll check it out.
> 
> Anyone else experience a problem like this?
> 
> Nate
> 
> On Tue, May 31, 2011 at 8:10 PM, Lawrence Pit <lawrence.pit@gmail.com> wrote:
>> Hi Nate,
>>> 
>>> We've been watching the CPU
>>> graphs from collectd data when the website is under load, and only
>>> cpu-0 shows any activity ... the others seem to be idle, or minimally
>>> used by other services.
>> 
>> I don't think you can rely on the numbers collectd (nor top) gives you when
>> measuring from within the hypervisor powering your EC2 instance. The only
>> reliable source of CPU utilization is Cloudwatch, as that measures outside
>> your instances.
>> 
>> I've used an array of xlarge instances myself, each running 17 unicorn
>> workers serving a rails app, consuming 4GB, leaving 3GB, no swap. Worked
>> well for us under high load. It couldn't have handled that if all 17 unicorn
>> workers would've been served by 1 of those 8 virtual cores.
>> 
>> 
>> Cheers,
>> Lawrence
>> 
>> 
> _______________________________________________
> Unicorn mailing list - mongrel-unicorn@rubyforge.org
> http://rubyforge.org/mailman/listinfo/mongrel-unicorn
> Do not quote signatures (like this one) or top post when replying
_______________________________________________
Unicorn mailing list - mongrel-unicorn@rubyforge.org
http://rubyforge.org/mailman/listinfo/mongrel-unicorn
Do not quote signatures (like this one) or top post when replying


  reply	other threads:[~2011-05-31 14:13 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-31  9:02 workers not utilizing multiple CPUs Nate Clark
2011-05-31 12:10 ` Lawrence Pit
2011-05-31 12:20   ` Nate Clark
2011-05-31 14:07     ` Clifton King [this message]
2011-05-31 15:48       ` Eric Wong
2011-05-31 15:55         ` Clifton King
     [not found]           ` <BANLkTikC5D+0pUDRDgvQbzu=dpwmdKNY=A@mail.gmail.com>
2011-06-01  6:51             ` Nate Clark
2011-05-31 15:27 ` Eric Wong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://yhbt.net/unicorn/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7E16F5B9-2C96-426F-BC75-670BEDD122A9@gmail.com \
    --to=cliftonk@gmail.com \
    --cc=lawrence.pit@gmail.com \
    --cc=mongrel-unicorn@rubyforge.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
Code repositories for project(s) associated with this public inbox

	https://yhbt.net/unicorn.git/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).