Description of problem: On httpd graceful restart httpd error log show up this: [Tue Mar 31 12:50:42 2009] [error] [client 127.1.2.3] (43)Identifier removed: apr_global_mutex_lock(rewrite_log_lock) failed [Tue Mar 31 12:50:42 2009] [error] [client 127.1.2.3] (43)Identifier removed: apr_global_mutex_unlock(rewrite_log_lock) failed Version-Release number of selected component (if applicable): Same Error show up in 2.2.11 upstream apache httpd release Steps to Reproduce: 1. Create directory /tmp/foo 2. Add (this) minimal server config foo-httpd.conf: --%<-- ServerRoot "/tmp/foo" DocumentRoot "/tmp/foo" PidFile /tmp/foo/foo-httpd.pid LoadModule rewrite_module /usr/lib/httpd/modules/mod_rewrite.so User nobody Group nobody ErrorLog foo-error_log RewriteLog foo-rewrite.log RewriteLogLevel 1 Listen 127.1.2.3:8765 <VirtualHost 127.1.2.3:8765> ServerName foo.bar RewriteEngine On RewriteOptions Inherit </VirtualHost> --%<-- 3. Start server: /usr/sbin/httpd -f /tmp/foo/foo-httpd.conf -k start 4. Do graceful restart: /usr/sbin/httpd -f /tmp/foo/foo-httpd.conf -k graceful 5. Find the apr_global_mutex_lock errors in /tmp/foo/foo-error_log Additional info: The error vanish if the RewriteLogLevel is set to 0 or the RewriteOptions Inherit ist _not_ set Kind Regards, Roland
mod_rewrite uses a global lock around calls to the logging function: - when logging is enabled, it takes this lock for each log entry written - when a graceful restart happens, the global lock is deleted even though it may still be used by existing child processes - those children will hence log an error if they fail to take the lock - if you are using the default MPM (prefork) not a threaded MPM (worker) this message is entirely harmless as the lock is entirely useless in that case anyway
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2009-1380.html