On Thu, 25.07.13 21:21, Tomasz Torcz (to...@pipebreaker.pl) wrote: > On Thu, Jul 25, 2013 at 06:51:21PM +0200, Lennart Poettering wrote: > > On Fri, 19.07.13 21:05, Pablo Nehab Hess (pa...@hess.net.br) wrote: > > > > > Hi all, > > > > > > I was wondering how much systemd could add to current high > > > availability cluster setups. > > > > > > Today systemd is used on HA clusters as just an init replacement. > > > However, there are systemd features that might come in handy and > > > improve the overall performance and even reliability of such clusters: > > > > > > * watchdog functionality as in > > > <http://0pointer.de/blog/projects/watchdog.html> is the most evident > > > feature; > > > * tcp-based dbus communication could be used to exchange information > > > between cluster members; > > > > > > Also, I believe systemd functionality could be extended so it would > > > take into consideration other nodes' systemd instances in order to > > > make sure each service is always alive somewhere -- call it "floating > > > units" if you will. :-) > > > > > > Does this idea even make sense? Is it too "one systemd to rule them all"? > > > > Well, I don't really know what exactly HA clusters would need. However, > > note that we actually do try to draw the line somewhere where systemd > > ends... I have the suspicion the HA cluster stuff something which could > > make great use of systemd's comprehensive bus interfaces, but I am not > > convinced such a project should sit in systemd itself. > > The RH Cluster suite cares about running services, and restarting services > when they fail. Just like systemd. Main difference is that you can select > on which host to run this service.
Well we have "-H" already. What more do you need? > It could be implemented in some daemon > synchronising state between remote systemd's. > Every time I use ”clustat” I feel like I'm should be looking at > ”systemctl status” listing. When I enable services using ”clusvcadm -e foo” > I feel like it should be ”systemctl enable foo”. There's a quite big > overlap between cluster suite and systemctl. So these tools will walk the cluster and get the status of the respective service on all machines? Lennart -- Lennart Poettering - Red Hat, Inc. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel