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From: Eric Wong <normalperson@yhbt.net>
To: unicorn list <mongrel-unicorn@rubyforge.org>
Subject: Re: Fwd: Maintaining capacity during deploys
Date: Thu, 29 Nov 2012 23:32:08 +0000	[thread overview]
Message-ID: <20121129233208.GB2618@dcvr.yhbt.net> (raw)
In-Reply-To: <CAHOTMVLYDbcdU4Q_jssiXF0AeEnui07U=4gUS9=T=wvLU9db7w@mail.gmail.com>

Tony Arcieri <tony.arcieri@gmail.com> wrote:
> We're using unicornctl restart with the default before/after hook
> behavior, which is to reap old Unicorn workers via SIGQUIT after the
> new one has finished booting.
> 
> Unfortunately, while the new workers are forking and begin processing
> requests, we're still seeing significant spikes in our haproxy request
> queue. It seems as if after we restart, the unwarmed workers get
> swamped by the incoming requests. As far as I can tell, the momentary
> loss of capacity we experience translates fairly quickly into a
> thundering herd.
> 
> We've experimented with rolling restarts at the server level but these
> do not resolve the problem.

So it's one haproxy -> multiple nginx/unicorn servers?

Do you mark the server down or lower the weight in haproxy when
deploying the Ruby app?  (Perhaps using monitor-uri in haproxy)

If the server is down to haproxy, but still up, you can send some warmup
requests to the server before enabling the monitor-uri for haproxy.
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  parent reply	other threads:[~2012-11-29 23:32 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAHOTMV++otgxdru_oZLXuVuqHF7F4uMwd04O0QZBjxeqFR-=XQ@mail.gmail.com>
2012-11-29 23:05 ` Fwd: Maintaining capacity during deploys Tony Arcieri
2012-11-29 23:09   ` Alex Sharp
2012-11-29 23:32   ` Eric Wong [this message]
2012-11-29 23:52     ` Fwd: " Tony Arcieri
2012-11-30 21:28     ` Tony Arcieri
2012-11-30 22:27       ` Eric Wong
2012-12-03 23:53         ` Tony Arcieri
2012-12-04  0:34           ` Eric Wong
2012-11-29 23:34   ` Lawrence Pit
2012-11-30  1:10     ` Tony Arcieri
2012-11-30  1:24       ` Eric Wong
2012-11-30  4:48         ` seth.cousins
2012-11-30  1:28     ` Devin Ben-Hur
2012-11-30  1:40       ` Tony Arcieri
2012-12-07 23:42 ` Tony Arcieri
2012-12-07 23:54   ` Eric Wong
2012-12-28 21:38   ` Dan Melnick
2012-12-28 22:07     ` Tony Arcieri

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