> Rainer Canavan <rainer.canavan <at> sevenval.com> writes: > > > we've got an obscure problem with the apache httpd that was shipped > > with CentOS 7.2. We perform automatic builds and updates via cron, > > and, since the update to CentOS 7.2. The update script is triggered by > > cron and stops, yum updates and starts the httpd. When the next cron > > job that is run as the same user as the httpd (not the update job) > > terminates, the httpd frequently fails, starting with a AH00273: > > apr_proc_mutex_lock failed message, and then a never ending loop of > > AH00272 messages, one from each httpd process that is forked, until > > the listener process is stopped. > > > Does anyone have any ideas what may cause these mutex errors? > > Sorry - no ideas, but I'm having the exact same issue, and have been trying > for the better part of a week to figure out what is causing this. Discussed with thumbs on IRC. Setting "Mutex sem" in my httpd.conf appears to be a work-around for this. Otherwise, it was unset, and would apparently default to "Mutex default". He suspected that "the apr package was botched by the RHEL maintainers". However, when I tried my compile-from-source work-around, it required a source include of both apr and apr-util, so I would think that could be discounted? Or possibly lead to a worse issue in something lower-level within RHEL/CentOS? But still worked-around by using sem - and would further explain why something like cron seems to need to be involved to reproduce? Frustratingly, reproducing this appears to be hit-and-miss. Following-up on my previous reply, I further did install mod_ssl and cloned over my complete configurations from the problem instance to my test instance, and was still unable to reproduce on a 2nd box with what I believe to be an identical build and configuration. We were curious if there was a way to determine if there was a way to know which implementation was being selected by default (and problematic), as both SYSVSEM and PTHREAD were defined in httpd -V (as shown below)? I also checked my compile-from-source work-around attempt, and using the Apache-provided defaults, everything related to the Mutex appeared to be identical. (Same 2 defines shown in httpd -V, and not explicit Mutex declaration in my httpd configuration files.) Is there anything further I can provide to help with this, even though it appears I may have a successful work-around? (Should a bug be opened for this on a tracker somewhere?) $ httpd -V Server version: Apache/2.4.6 (CentOS) Server built: Nov 19 2015 21:43:13 Server's Module Magic Number: 20120211:24 Server loaded: APR 1.4.8, APR-UTIL 1.5.2 Compiled using: APR 1.4.8, APR-UTIL 1.5.2 Architecture: 64-bit Server MPM: worker threaded: yes (fixed thread count) forked: yes (variable process count) Server compiled with.... -D APR_HAS_SENDFILE -D APR_HAS_MMAP -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled) -D APR_USE_SYSVSEM_SERIALIZE -D APR_USE_PTHREAD_SERIALIZE -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT -D APR_HAS_OTHER_CHILD -D AP_HAVE_RELIABLE_PIPED_LOGS -D DYNAMIC_MODULE_LIMIT=256 -D HTTPD_ROOT="/etc/httpd" -D SUEXEC_BIN="/usr/sbin/suexec" -D DEFAULT_PIDLOG="/run/httpd/httpd.pid" -D DEFAULT_SCOREBOARD="logs/apache_runtime_status" -D DEFAULT_ERRORLOG="logs/error_log" -D AP_TYPES_CONFIG_FILE="conf/mime.types" -D SERVER_CONFIG_FILE="conf/httpd.conf" --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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