Re: [Xen-devel] Problem Xen 4.0-amd64 + Heartbeat 3.0.3-2 with Debian Squeeze

[Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>]

(please try not to top post and always leave the CC to xen-devel in
tact)

On Tue, 2011-05-31 at 15:45 +0100, gilmarlinux@xxxxxxxxxxxxxxx wrote:
> Thank you for your help.
> Yesterday increase the values ââof the heartbeat configuration as
> below.
> 
> /etc/ha.d/ha.cf
> keepalive 15
> deadtime 50
> warntime 30

What are the units of these values? I seem to recall it was complaining
of delays of the order 300ms, so you'd presumably want to be sure they
were longer than that.

Ian.


> 
> Liberie also the suggestion, I will now await the return message
> appears in the logs or not.
> 
> > On Sat, 2011-05-28 at 22:21 +0100, gilmarlinux@xxxxxxxxxxxxxxx
> wrote:
> >> I thought it might be something I / O xen causing this in
> heartbeat.
> > 
> > "I / O"? I'm not sure what this means.
> > 
> > I wonder if this is just simply down to scheduling latencies? i.e.
> dom0
> > simply isn't getting scheduled frequently enough to meet the
> > requirements of the heartbeat process.
> > 
> > I assume this doesn't happen when there is no domU workload to
> contend
> > with dom0? What sort of workloads are your guests running? How many
> > VCPUs do you have in total?
> > 
> > As an experiment you could try playing with the scheduling
> priorities
> > for dom0, e.g. giving it more weight.
> > 
> > Another experiment you could try is pinning a dom0 VCPU to a PCPU,
> > pinning the heartbeat process to that VCPU and excluding domU VCPUs
> from
> > contention by pinning them to the remaining PCPUs.
> > 
> > IIRC these sorts of latency sensitive workloads are somewhere that
> the
> > existing credit scheduler doesn't do so well and is something which
> > George is looking to address with credit2. His canonical workload of
> > this type is audio playback but I suppose heartbeat falls into the
> same
> > broad class. So it might also be worth trying the credit2 scheduler.
> > 
> > You could also try Xen 4.1, IIRC some band-aids were applied to the
> > credit1 scheduler between 4.0 and 4.1.
> > 
> > Lastly you could presumably configure heartbeat to be less sensitive
> to
> > these latencies? I also hope that the heartbeat process sets itself
> up
> > with the Linux scheduler to be a fairly high priority process within
> > dom0?
> > 
> > Ian.
> > 
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> >



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