Hi, On Wed, Jul 11, 2012 at 08:40:13PM +0200, Michael Schwartzkopff wrote: > > > > Hi, > > > > > > > > I would like to build a HA Solution with 2 servers with 1 in > > > > hot-standy i.e. fail-over. The advice so far was to use GlusterFS > > > > (replicated) for the filesystem and mysql replication (master-slave) > > > > for the database. The purpose is a web server (apache) with a typo3 > > > > CMS. > > > > > > > > In the event of a failure I need to run a script to perform the actual > > > > failover (switch ip via web request (Hetzner robot) and change mysql > > > > replication settings). > > > > > > > > Would you recommend to use corosync/pacemaker to monitor the > > > > > > database, > > > > > > > gluster and apache or should I simply check the availability of a DB > > > > generated Web Page from a script in a loop? > > > > > > > > Any other recommendations? > > > > > > Yes! > > > Set up real cluster, use DRBD to replicate the data between the nodes and > > > pacamaker to monitor the resources (IP, filesystem, database and > > > webserver). > > > pacemaker will do the failover in case of problems. > > > > > > See: http://www.linbit.at/training/webseminare-auf-abruf/mysql- > > > replikation- > > > mit-pacemaker/ > > > > > > > Since I don't have a lot of corosync experience it seems to me like a > > > > huge task (overkill) for a simple monitoring of a failover scenario. > > > > > > > > What do you think? > > > > > > I heard there is a very good book from O'Reilly ;-) > > > > > > Greetings, > > > > > > -- > > > Dr. Michael Schwartzkopff > > > > Hi Michael, > > > > the problems starts when I start to think about fencing: I am working with > > a standard root server, it simply doesn't have a STONITH hardware. I've > > read various threads which basically say if you don't have proper fencing > > when it's all your fault ... You don't really suggest to use the > > ssh-stonith for production ... > > STONITH idea for Hetzner: > http://lists.linux-ha.org/pipermail/linux-ha/2011-May/043187.html
external/hetzner is distributed with cluster-glue. Thanks, Dejan > > I could externally trigger a hardware reset > > of a machine and reroute the ip to the other server. Would that be a valid > > stonith action? I did actually like the book, but fencing takes some fun > > out of the whole setup (makes it a lot more complicated). Also I tend to > > believe it's best to use the database replication methods if available > > rather than do it via the file system. > > DRBD is block replication, not file system sync. > > > I didn't like drbd too much, since there is no easy way to gain access to > > the filesystem on the slave machine. I never got the whole stack in dual > > primary mode with ocfs2 running. Gluster easily provides for this. > > > > Stefan > > > > P.s. :-) I did actually like the book, but the fencing part is a killer > > I would be happy on a 5-star comment on amazon ;-) > > Do as you like. But setting up a Linux Cluster including fencing and DRBD is > not a big deal. And if your compare it with writing your own failover scripts > ... > > -- > Dr. Michael Schwartzkopff > Guardinistr. 63 > 81375 München > > Tel: (0163) 172 50 98 > _______________________________________________ > 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
