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From: Yann Ylavic <ylavic.dev@gmail.com>
Date: Wed, 22 Mar 2017 14:38:08 +0100
Message-ID: <CAKQ1sVP341QUyzQwx8_zd9fn6gnJF4d-Vwx6HrWxWeZhjX4E1w@mail.gmail.com>
Subject: Re: listener buckets regressions
To: httpd-dev <dev@httpd.apache.org>
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archived-at: Wed, 22 Mar 2017 13:38:14 -0000

On Wed, Mar 15, 2017 at 10:29 AM, Joe Orton <jorton@redhat.com> wrote:
> There seems to be some weird regressions in this.  A mis-configuration
> like:
>
> Listen 127.0.0.1:8025
> Listen [::1]:8025
> Listen 127.0.0.1:8025
> Listen [::1]:8025
> ListenCoresBucketsRatio 8
>
> ... no longer triggers a startup failure - is that expected?  I guess it
> should be documented if so.

Yes, SO_REUSEPORT allows multiple processes with the same EUID to bind
the same port.
I guess it's more a side effect than a feature from httpd's
perspective (albeit it possibly could have an application...), in any
case I agree that it should be documented (will have a look at it).

>
> Such a config then leaks fds across reloads:
>
> $ ss -ntlp | grep :8025 | wc -l
> 8
> $ ./bin/apachectl graceful
> $ ss -ntlp | grep :8025 | wc -l
> 10
> $ ./bin/apachectl graceful
> $ ss -ntlp | grep :8025 | wc -l
> 12
>
> Maybe somebody familiar with the code can understand why.

Will try...

>
> These issues are a regression in 2.4.x without ListenCoresBucketsRatio
> set as well, which the below seems to fix (proposed for backport):
>
> http://svn.apache.org/viewvc?view=revision&revision=1777923

Seems to be backported already, good thing.


Regards,
Yann.