On 22/06/16 08:30 AM, Lentes, Bernd wrote: > Hi, > > we have a two node cluster. It is running a Web-Application. Web-Application > needs a MySQL Database, has static and dynamic (perlscripts) webpages. > I will make the DB HA with MySQL replication. > From time to time it's likely that something in the webapp is changed, so we > have to edit some scripts or install a perl module. > I would like have the changes automatically synchronized to the other side, > without any manual intervention. And also without knowing which node is the > active one. > I'm thinking about putting /srv/www and /usr/lib/perl5 on a DRBD device in an > active/active webapp. For that i need a cluster FS and DLM, right ? > This should synchronize automatically in both directions ? > Do the services have to a ressource for this setup of DRBD or is it possible > to have them as "normal" services, started by init. > Or is it better to have them as ressources because other services will also > run in this HA-system (likely some virtual machines) ? > > Thanks. > > > Bernd
Our approach to this problem is a 2-node cluster using DRBD to back virtual machines, and then we make he VMs the HA service. This way, to you and whomever works on the system, you can ignore the HA stuff and treat it like a regular server. If anything happens to the current host, the server reboots on the good node. Being a VM, reboots are generally quite quick. We've detailed how we build our system in detail here: https://alteeve.ca/w/AN!Cluster_Tutorial_2 However, you may want to use pacemaker instead of cman+rgmanager. In that case, the tutorial above is still useful as it explains the approach. You can just mentally switch "cman+rgmanager" for "pacemaker", adjust the actual commands and the rest of the guide works fine. -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education? _______________________________________________ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org