From: Suraj Kurapati <sunaku@gmail.com>
To: unicorn list <mongrel-unicorn@rubyforge.org>
Subject: zero downtime deploys
Date: Fri, 13 Nov 2009 14:54:05 -0800 [thread overview]
Message-ID: <cfbcd2f00911131454sf4e572ap2847067a59b8dc8c@mail.gmail.com> (raw)
Hello,
I tried using preload_app with the "zero downtime deploys" trick of
sending SIGQUIT to the old master in before_fork(), as described in:
http://unicorn.bogomips.org/Unicorn/Configurator.html
http://github.com/blog/517-unicorn
This significantly reduced, but did not eliminate, the transition time
when the new workers take over (step #2 below):
1. old master (and its workers) is killed in before_fork()
2. workers re-establish DB connections in after_fork()
3. workers are ready to work, at the bottom of after_fork()
Why do we kill the old master in before_fork() when the new workers
are really ready to work much later? Shouldn't we kill the old master
at the *bottom* of after_fork() --- when the new workers are really
ready to work?
Thanks for your consideration.
next reply other threads:[~2009-11-13 22:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-13 22:54 Suraj Kurapati [this message]
2009-11-13 23:12 ` zero downtime deploys Eric Wong
2009-11-13 23:25 ` Suraj Kurapati
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