unicorn Ruby/Rack server user+dev discussion/patches/pulls/bugs/help
 help / color / mirror / code / Atom feed
From: Eric Wong <e@80x24.org>
To: Kevin Yank <kyank@avalanche.com.au>
Cc: unicorn-public@bogomips.org
Subject: Re: On USR2, new master runs with same PID
Date: Fri, 20 Mar 2015 02:08:36 +0000	[thread overview]
Message-ID: <20150320020836.GA32651@dcvr.yhbt.net> (raw)
In-Reply-To: <31B22118-FCD4-4909-AB6F-47F99A05F111@avalanche.com.au>

Kevin Yank <kyank@avalanche.com.au> wrote:
> Regarding zero-downtime deploys:
> On 12 Mar 2015, at 5:45 pm, Eric Wong <e@80x24.org> wrote:
> > Best bet would be to run with double the workers temporarily unless
> > you're too low on memory (and swapping) or backend (DB) connections or
> > any other resource.
> I’d like to take this approach as I do have enough memory to spare.
> How do you usually implement this? Any good write-ups or sample
> configs you can point me to?

Only send SIGUSR2 to the master, leaving you with two masters and two
sets of workers.  Skip (automated) sending of SIGTTOU signals to lower
worker count to the old master.

Eventually, you'll decide to send SIGQUIT to the old master to stop
it (or the new one, if you decide the new code is broken).

You can still combine this with SIGWINCH (or SIGTTOU) to stop traffic
flow to the old master, too.

Thanks for following up on your logrotate/eye issue, by the way.

      reply	other threads:[~2015-03-20  2:08 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-12  1:04 On USR2, new master runs with same PID Kevin Yank
2015-03-12  1:45 ` Eric Wong
2015-03-12  6:26   ` Kevin Yank
2015-03-12  6:45     ` Eric Wong
2015-03-20  1:55       ` Kevin Yank
2015-03-20  1:58       ` Kevin Yank
2015-03-20  2:08         ` Eric Wong [this message]

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:

  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=20150320020836.GA32651@dcvr.yhbt.net \
    --to=e@80x24.org \
    --cc=kyank@avalanche.com.au \
    --cc=unicorn-public@bogomips.org \


* 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


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).