Bug 60825 - [core:emerg] File exists: AH00023: Couldn't create the watchdog-callback mutex (file /var/run/watchdog-callback-_proxy_hcheck_)
Summary: [core:emerg] File exists: AH00023: Couldn't create the watchdog-callback mute...
Status: RESOLVED FIXED
Alias: None
Product: Apache httpd-2
Classification: Unclassified
Component: mod_proxy_hcheck (show other bugs)
Version: 2.4.25
Hardware: PC FreeBSD
: P2 major (vote)
Target Milestone: ---
Assignee: Apache HTTPD Bugs Mailing List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-03-06 20:39 UTC by Rustam Abdullaev
Modified: 2019-06-14 05:40 UTC (History)
1 user (show)


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Description Rustam Abdullaev 2017-03-06 20:39:02 UTC 
mod_proxy_hcheck in 2.4.25 causes httpd to terminate on SIGUSR1.

How to reproduce:

1. install httpd 2.4.25 (tried on FreeBSD 11 amd64)

2. enable modules:
LoadModule watchdog_module libexec/apache24/mod_watchdog.so
LoadModule proxy_module libexec/apache24/mod_proxy.so
LoadModule proxy_hcheck_module libexec/apache24/mod_proxy_hcheck.so

3. start httpd

4. Send a graceful restart signal (USR1) to httpd:
kill -30 `cat /var/run/httpd.pid`

5. Notice httpd alive no more.

Error log contains:
[Mon Mar 06 21:30:16.675109 2017] [mpm_prefork:notice] [pid 1911] AH00171: Graceful restart requested, doing restart
[Mon Mar 06 21:30:16.764517 2017] [core:emerg] [pid 1911] (17)File exists: AH00023: Couldn't create the watchdog-callback mutex (file /var/run/watchdog-callback-_proxy_hcheck_.1911)
[Mon Mar 06 21:30:16.764567 2017] [:emerg] [pid 1911] AH00020: Configuration Failed, exiting
Comment 1 Jim Jagielski 2017-03-22 17:52:00 UTC 
Does the file exist? It looks like this is due to the graceful restart and the file not being cleaned and/or ignored
Comment 2 Jim Jagielski 2017-03-31 11:59:21 UTC 
Ahhh... I think the issue is fixed via:

 https://svn.apache.org/viewvc/httpd/httpd/trunk/modules/proxy/mod_proxy_hcheck.c?r1=1784275&r2=1785871&diff_format=h

proposed for back port
Comment 3 Christophe JAILLET 2019-06-14 05:40:24 UTC 
This has been backported in r1792905.

This is part of 2.4.26.


If you still encounter the issue, please reopen this bug report.