[Pacemaker] meaning of Monitor Interval

[Xiaomin Zhang]

Hello Lars:
I'm still somewhat not clear about this monitor interval setting. What I
observed is that the pacemaker always quickly (in less then 2 seconds)
schedule the failed resource when I just cut down the network (via DROP
INPUT, or freeze kernel).
And it also schedule the failed resource in no more than 5 seconds while I
put the online node to standby state.
Is there wrong assumption made by me?
Thanks.


On Fri, Sep 13, 2013 at 2:45 PM, Lars Marowsky-Bree <lmb at suse.com> wrote:

> On 2013-09-13T12:20:54, Xiaomin Zhang <zhangxiaomin at gmail.com> wrote:
>
> > Hi, Gurus:
> > Here's a question about service Monitor Interval: considering this value
> is
> > configured as '15' seconds, does this mean corosync/pacemaker will take
> > average 15 seconds to schedule failed resource on a ready node?
>
> It'll take about a maximum of 15 seconds to schedule a monitoring
> operation that can detect the error.
>
> If the monitor operation returns within <1s with a failure, that'll mean
> the recovery will begin real quick.
>
> If the monitor operation *doesn't* return but hit it's "timeout" (and is
> aborted by the lrmd), then the recovery will be delayed by that much. So
> for an ``interval=15 timeout=30'', it could take up to 45s before
> recovery is scheduled.
>
> Note however this on timeouts:
> http://advogato.org/person/lmb/diary/108.html Just making them shorter
> isn't necessarily always beneficial, either.
>
>
> Best,
>     Lars
>
> --
> Architect Storage/HA
> SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix
> Imendörffer, HRB 21284 (AG Nürnberg)
> "Experience is the name everyone gives to their mistakes." -- Oscar Wilde
>
>
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