Hi, On Thu, Oct 14, 2010 at 04:15:12PM -0400, Buckingham, Brett wrote: > I'm new to Pacemaker / OpenAIS / Corosync / Linux-HA, and have been > going through the "Clusters from Scratch v2" tutorial at > http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf. > > I could not get the CRM to start apache, but could start it directly via > "/etc/init.d/httpd start". My symptoms were identical to that > described in the Pacemaker mailing list post: > http://www.mail-archive.com/[email protected]/msg02479.html > > /var/log/httpd/error.log seemed to suggest that apache was starting, > then catching a SIGTERM 1 second later. > > I tried the suggested solutions (ensuring that apache's PidFile and > ExtendedStatus were enabled), but this didn't work. > > I debugged the RA directly, and found what I believe to be a race > condition in the monitor_apache() function. The first thing it does is > to call silent_status(), which basically checks to see if there is a PID > file for apache, and that there is a running process with that PID. If > that is true, it then calls monitor_apache_basic(), which, with my > configuration, wget's http://localhost:80. If the wget fails, return > code 1 is passed upwards. > > The race condition is that when apache is started, it is possible for it > to have written it's PID file, but not yet completed its initialization > to the point where the wget would succeed. I was able to work around > this problem by placing a simple "sleep 5" after starting httpd and the > first call to monitor_apache(). > > I'm running Fedora 13 as a VirtualBox VM guest on a Win7 host, Pacemaker > 1.1.3, Corosync 1.2.8, and apache RA from resource-agents 3.0.16. > > I would appreciate it if someone more familiar with this RA could > double-check my theory.
Sounds plausible. Interestingly, nobody so far reported this. The usual problem with apache is that people don't load or setup correctly the status module. I suppose that that's not the case here. Thanks, Dejan > Cheers, > Brett > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
