Mailing-List: contact dev-help@httpd.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@httpd.apache.org
MIME-Version: 1.0
In-Reply-To: <43c3a7ed-e86b-1543-a18f-255e747ad680@profihost.ag>
References: <43c3a7ed-e86b-1543-a18f-255e747ad680@profihost.ag>
From: Luca Toscano <toscano.luca@gmail.com>
Date: Thu, 16 Mar 2017 12:26:13 +0100
Message-ID: <CAFedD43VF7694m87eFTTj13XWhMNNG9_wkg+HdYgkpyXMba6UQ@mail.gmail.com>
Subject: Re: Apache 2.4.26 AH: scoreboard is full, not at MaxRequestWorkers.Increase,ServerLimit
To: Apache HTTP Server Development List <dev@httpd.apache.org>
Content-Type: multipart/alternative; boundary=001a114af65e2acb77054ad7545d
archived-at: Thu, 16 Mar 2017 11:32:28 -0000

--001a114af65e2acb77054ad7545d
Content-Type: text/plain; charset=UTF-8

Hi Stefan,

2017-03-16 12:14 GMT+01:00 Stefan Priebe - Profihost AG <
s.priebe@profihost.ag>:

> Hi Yann,
>
> no sure whether this is due to your mpm event patch.
>
> From time to time i see the following error mesages in my logs and the
> only chance to fix it is to restart apache.
>
> [Thu Mar 16 01:00:35.445184 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
> [Thu Mar 16 01:00:36.446178 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
> [Thu Mar 16 01:00:37.447181 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
> [Thu Mar 16 01:00:38.448177 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
> [Thu Mar 16 01:00:39.449185 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
> [Thu Mar 16 01:00:40.450184 2017] [mpm_event:error] [pid 27485:tid
> 140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase
> ServerLimit.
>
> Settings:
>         ServerLimit           50
>         ThreadLimit           200
>         ThreadsPerChild        200
>         MinSpareThreads        200
>         MaxSpareThreads        400
>         MaxClients             10000
>         MaxRequestsPerChild    10000
>
> MaxRequestWorkers isn't set at all.
>

I believe that MaxClients (its old name) takes the place of
MaxRequestWorkers, but it is set as the default value (ServerLimit *
ThreadsPerChild). From 2.4.25 onwards mpm-event offers a new functionality
to handle Gracefully terminating processes (
https://httpd.apache.org/docs/current/mod/event.html#how-it-works), but it
must be tuned raising the value of ServerLimit (more details in the docs).

This is only a speculation from my side, to have a better idea of what's
happening it would be great to see how the Scoreboard looks like in server
status, and if the error status happens during specific events like
graceful reload for log rotation.

Hope that helps! As always, thanks a lot for your tests :)

Luca

--001a114af65e2acb77054ad7545d
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Hi Stefan,<div class=3D"gmail_extra"><br><div class=3D"gma=
il_quote">2017-03-16 12:14 GMT+01:00 Stefan Priebe - Profihost AG <span dir=
=3D"ltr">&lt;<a href=3D"mailto:s.priebe@profihost.ag" target=3D"_blank">s.p=
riebe@profihost.ag</a>&gt;</span>:<br><blockquote class=3D"gmail_quote" sty=
le=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);paddi=
ng-left:1ex">Hi Yann,<br>
<br>
no sure whether this is due to your mpm event patch.<br>
<br>
From time to time i see the following error mesages in my logs and the<br>
only chance to fix it is to restart apache.<br>
<br>
[Thu Mar 16 01:00:35.445184 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
[Thu Mar 16 01:00:36.446178 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
[Thu Mar 16 01:00:37.447181 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
[Thu Mar 16 01:00:38.448177 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
[Thu Mar 16 01:00:39.449185 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
[Thu Mar 16 01:00:40.450184 2017] [mpm_event:error] [pid 27485:tid<br>
140212799559552] AH: scoreboard is full, not at MaxRequestWorkers.Increase<=
br>
ServerLimit.<br>
<br>
Settings:<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 ServerLimit=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A050<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 ThreadLimit=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0200<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 ThreadsPerChild=C2=A0 =C2=A0 =C2=A0 =C2=A0 200<=
br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 MinSpareThreads=C2=A0 =C2=A0 =C2=A0 =C2=A0 200<=
br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 MaxSpareThreads=C2=A0 =C2=A0 =C2=A0 =C2=A0 400<=
br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 MaxClients=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A010000<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 MaxRequestsPerChild=C2=A0 =C2=A0 10000<br>
<br>
MaxRequestWorkers isn&#39;t set at all.<br></blockquote><div><br></div><div=
>I believe that MaxClients (its old name) takes the place of MaxRequestWork=
ers, but it is set as the default value (ServerLimit * ThreadsPerChild). Fr=
om 2.4.25 onwards mpm-event offers a new functionality to handle Gracefully=
 terminating processes (<a href=3D"https://httpd.apache.org/docs/current/mo=
d/event.html#how-it-works">https://httpd.apache.org/docs/current/mod/event.=
html#how-it-works</a>), but it must be tuned raising the value of ServerLim=
it (more details in the docs).</div><div><br></div><div>This is only a spec=
ulation from my side, to have a better idea of what&#39;s happening it woul=
d be great to see how the Scoreboard looks like in server status, and if th=
e error status happens during specific events like graceful reload for log =
rotation.=C2=A0</div><div><br></div><div>Hope that helps! As always, thanks=
 a lot for your tests :)</div><div><br></div><div>Luca=C2=A0</div></div></d=
iv></div>

--001a114af65e2acb77054ad7545d--