On Thu, Nov 8, 2012 at 5:24 PM, Gao,Yan <y...@suse.com> wrote: > Hi Andrew, > > On 11/08/12 13:09, Andrew Beekhof wrote: >> On Tue, Nov 6, 2012 at 10:30 PM, Gao,Yan <y...@suse.com> wrote: >>> Hi, >>> >>> Currently, we can manage VMs via the VM agents. But the services running >>> within VMs are not very easy to be monitored. If we could use >>> nagios/icinga probes from the host to the guest, that would allow us to >>> achieve this. >>> >>> Lars, Dejan and I have been discussing on this for some time. There have >>> been quite some thoughts on how to implement it. Now we are inclined to >>> a proposal from Lars. Please let me introduce the idea here, and see >>> what you think about it. >>> >>> First, we could add a resource agent class. The RAs belonging to this >>> class wrap around nagois/icinga probes. They can be configured as >>> special monitor operations for the VMs. The behaviors should be like: >>> >>> 1. The special monitor operations start working after the VMs and the >>> services inside are started. >>> >>> 2. Any failure of the monitor operations is treated as the failure of >>> the VM, which triggers the recovery of the VM. >>> >>> Let me show a example: >>> >>> primitive db-vm ocf:heartbeat:VirtualDomain \ >>> params config="db-vm" hypervisor="xen:///" \ >>> ip="192.168.1.122" \ >>> op monitor nagios:ftp interval="30s" params user="test" >>> >>> The "nagios:ftp" specifies which monitor agent is used to monitor the >>> VM. It's an optional attributes group expressing "class/provider/type" >>> of the monitor agent, which defaults to "ocf:heartbeat:VirtualDomain" >>> for this VM (if so, the monitor would be a normal one like we usually >>> configure). We can add more monitors like "nagios:www" type and so on. >> >> What do you propose the XML should look like? > Should be like: > ... > <op id="vm-monitor-30" name="monitor" class="nagios" type="ftp" > interval="30s" ignore-first-failures="true"> > <instance_attributes id="vm-monitor-30-params"> > <nvpair id="vm-monitor-30-params" name="user" value="test"> > </instance_attributes> > </op> > ... > >> >>> We can specify particular "params" for a monitor. And the "ip" is >>> actually not a useful parameter for the VirtualDomain, we put it there >>> for its monitor operations to inherit, so that we don't have to specify >>> for each monitor respectively. >> >> You plan to add 'ip' to the VirtualDomain metadata? > It should be in the metatdata of nagios:ftp and also other monitor > agents. We'd like parameters inheritance to avoid configuration repetition.
That sounds overly complex (you now need to do two metadata lookups to determine the parameter lists). I think I'd prefer to avoid that if possible. > >> >>> >>> >>> Other issues: >>> - As we can see, there's some time window between when the VM is >>> started, but prior to the monitored service starting. A solution is >>> adding a "first-failure" flag for the monitor operation, which could >>> allow us to ignore the *first* failures of a monitor until it has >>> returned healthy once, unless the time is out. Ideally, it could be >>> handled in LRM. >> >> What happens if there is never a first success? >> The cluster will never find out. > It'll reach the timeout and return. Which timeout? Not the one in <op...> since the whole operation might repeat many times over before succeeding. > We should give a reasonable monitor > timeout I think. > >> >>> >>> - A limitation is we would have to specify different monitor interval >>> values for the services within a VM. Probably we could fix it in some >>> way finally. >>> >>> >>> Anyway, this's the most straightforward solution we can think of so far >>> (Please correct me if I'm missing anything). It's open for discussion. >>> Any comments and suggestions are welcome and appreciated. >> >> Doesn't look too bad. Some finer points to discuss but I'm sure we >> can reach agreement. > Nice, thanks! > > Regards, > Gao,Yan > -- > Gao,Yan <y...@suse.com> > Software Engineer > China Server Team, SUSE. > > _______________________________________________ > 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 _______________________________________________ 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
