On Wed, Jan 25, 2012 at 2:22 AM, Dejan Muhamedagic <deja...@fastmail.fm> wrote: > On Tue, Jan 24, 2012 at 03:11:31PM +1100, Andrew Beekhof wrote: >> On Tue, Jan 24, 2012 at 7:20 AM, Dejan Muhamedagic <deja...@fastmail.fm> >> wrote: >> > On Mon, Jan 23, 2012 at 08:55:02AM +1100, Andrew Beekhof wrote: >> >> On Sat, Jan 21, 2012 at 12:18 AM, Dejan Muhamedagic <deja...@fastmail.fm> >> >> wrote: >> >> > On Fri, Jan 20, 2012 at 01:09:56PM +1100, Andrew Beekhof wrote: >> >> >> On Thu, Jan 19, 2012 at 12:15 AM, Dejan Muhamedagic >> >> >> <deja...@fastmail.fm> wrote: >> >> >> > On Wed, Jan 18, 2012 at 06:58:20PM +1100, Andrew Beekhof wrote: >> >> >> >> On Wed, Jan 18, 2012 at 6:00 AM, Dejan Muhamedagic >> >> >> >> <deja...@fastmail.fm> wrote: >> >> >> >> > Hello, >> >> >> >> > >> >> >> >> > On Tue, Jan 03, 2012 at 05:19:14PM +1100, Andrew Beekhof wrote: >> >> >> >> >> Does anyone have an opinion on the following schema and example? >> >> >> >> >> I'm not a huge fan of the index field, but nor am I of making it >> >> >> >> >> sensitive to order (like groups). >> >> >> >> > >> >> >> >> > What is wrong with order in XML elements? It seems like a very >> >> >> >> > clear way to express order to me. >> >> >> >> >> >> >> >> Because we end up with the same update issues as for groups. >> >> >> > >> >> >> > OK. >> >> >> > >> >> >> > [...] >> >> >> > >> >> >> >> > Is there a possibility to express >> >> >> >> > fencing nodes simultaneously? >> >> >> >> >> >> >> >> No. Its regular boolean shortcut semantics. >> >> >> > >> >> >> > As digimer mentioned, it is one common use case, i.e. for hosts >> >> >> > with multiple power supplies. So far, we recommended lights-out >> >> >> > devices for such hardware configurations and if those are >> >> >> > monitored and more or less reliable such a setup should be fine. >> >> >> > It would still be good to have a way to express it if some day >> >> >> > somebody actually implements it. I guess that the schema can be >> >> >> > easily extended by adding a "simultaneous" attribute to the >> >> >> > "fencing-rule" element. >> >> >> >> >> >> So in the example below, you'd want the ability to not just trigger >> >> >> the 'disk' and 'network' devices, but the ability to trigger them at >> >> >> the same time? >> >> > >> >> > Right. >> >> >> >> For any particular reason? Or just in case? >> > >> > For nodes with multiple PSU and without (supported) management >> > board. >> >> That still doesn't explain why the 'off' commands would need to be >> simultaneous though. >> To turn the node off, both devices just need to turn the port off... >> there's no requirement that this happens simultaneously. > > OK, right. What I had in mind was actually the default reset > action. > >> > I think that one of our APC stonith agents can turn more >> > than one port off simultaneously. >> >> If they're for the same host and device, then you don't even need this. >> Just specify two ports in the host_map. > > Cool. Didn't look into it. How would that work with say > external/rackpdu (uses snmpset(8) to manage ports)?
We'll supply something like port=1,2 or port=1-3 and its up to the agent to map that into something the device understands. > That agent > can either use the names_oid to fetch ports by itself (in which > case they must be named after nodes) or this: > > outlet_config (string): Configuration file. Other way to > recognize outlet number by nodename. > Configuration file. Other way to recognize outlet number by nodename. > Configuration file which contains > node_name=outlet_number > strings. > > Example: > server1=1 > server2=2 > > Now, how does stonithd know which parameter to use to pass the > outlet (port) number from the host_map list to the agent? Item 6: http://www.clusterlabs.org/doc/en-US/Pacemaker/1.1/html/Pacemaker_Explained/s-stonith-configure.html I do try to document these things. > I > assume that the agent should have a matching API. Does this work > only with RH fence agents? > >> If they're not for the same host, then they're not even covered by the >> same fencing operation and will never be simultaneous. >> >> If they're for the same host but different devices, then at most >> you'll get the commands sent in parallel, guaranteeing simultaneous is >> near impossible. > > Yes, what I meant is almost simultaneous, i.e. that both ports > are for a while turned "off" at the same time. I'm not sure how > does it work in reality. For instance, how long does the reset > command keep the power off on the outlet. So, it should be > "simultanous enough" :) I dont think 'reboot' is an option if you're using multiple devices. You have to use 'off' (followed by a manual 'on') for any kind of reliability. Agents that fake 'reboot' with 'off' + sleep + 'on' would be ok, but thats an implementation detail that the daemon shouldn't know about. _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
