Hi Andrew, "Andrew Beekhof" <[EMAIL PROTECTED]> wrote: > On 11/5/07, Sebastian Reitenbach <[EMAIL PROTECTED]> wrote: > > Hi, > > > > to remove complexity from my cluster, I am experimenting with Xen. > > Starting and stopping the Xen resources via heartbeat works well already. > > I am a bit concerned about the services in the virtual machines, how is the > > best approach to monitor their availability? > > what you're talking about is basically having the crm manage resources > on non-cluster nodes. > > we've kicked around some ideas for implementing this in the past but > its never really bubbled to the top of anyone's todo list. > > there's not really any "best practices" for this as its not really > being done a whole lot (from what I hear anyway). depending on how > complex the relationships between the resources inside the Xen guests > are, i'd go with option 1 (if they're complex) or 2 (if not)
thank you for your comments. I more or less have to check that the services not get killed by the OOM killer, e.g. when i have 3 domU's running, and I want to start a 4. node, but I have no free memory, available, then I have to shrink the memory of the already running domU's via xen'S mem-set. But when I do that, it can happen that the OOM killer in the domU will kill my services, that the domU is intended to provide. Unfortunately, heartbeat has nothing to detect that, yet. I am just tweaking the Xen resource script. I added a parameter, OCF_RESKEY_monitor_scripts, that the Xen resource script will run when the monitor action for the domU is called. These custom scripts will test the services assigned to the domU, in case one fails, then the whole domU will be restarted via heartbeat, and then hopefully get the internal service restarted too. Sebastian > > > > > I have some solutions, but would like to know what corresponds to best > > practice: > > > > - install heartbeat in the virtual domains too, then monitor the resources > > within the xen instance, but I think this is counterproductive as I wanted > > to remove complexity from the cluster due to having less resources. > > > > - monitor the services in the virtual domains using SNMP, or custom scripts, > > and in case sth. fails, crm_resource stop and setart it again. Well, custom > > scripts sounds a bit error prone. > > > > - I don't know whether xen has the ability, but does the priviliged domain > > has the ability to query a given domU for the state of a process, and in > > case the state is just not the wanted one, restart the domU. > > > > I think the last one, would be the best, but I have no idea, whether xen can > > do that at all. I played around with OpenVZ for a short while, that at least > > could do that. Any other ideas, comments, rants are very welcome. > > > > kind regards > > Sebastian > > > > _______________________________________________ > > 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
