[ClusterLabs] Antw: Re: Gracefully stop nodes one by one with disk-less sbd

[Ulrich Windl]

>>> Andrei Borzenkov <arvidjaar at gmail.com> schrieb am 09.08.2019 um 18:40 in
Nachricht <217d10d8-022c-eaf6-28ae-a4f58b2f97af at gmail.com>:
> 09.08.2019 16:34, Yan Gao пишет:
>> Hi,
>> 
>> With disk-less sbd,  it's fine to stop cluster service from the cluster 
>> nodes all at the same time.
>> 
>> But if to stop the nodes one by one, for example with a 3-node cluster, 
>> after stopping the 2nd node, the only remaining node resets itself with:
>> 
> 
> That is sort of documented in SBD manual page:
> 
> --><--
> However, while the cluster is in such a degraded state, it can
> neither successfully fence nor be shutdown cleanly (as taking the
> cluster below the quorum threshold will immediately cause all remaining
> nodes to self-fence).
> --><--
> 
> SBD in shared-nothing mode is basically always in such degraded state
> and cannot tolerate loss of quorum.

So with a shared device it'S different? I was wondering whether
"no-quorum-policy=freeze" would still work with the recent sbd...

> 
> 
> 
>> Aug 09 14:30:20 opensuse150-1 sbd[1079]:       pcmk:    debug: 
>> notify_parent: Not notifying parent: state transient (2)
>> Aug 09 14:30:20 opensuse150-1 sbd[1080]:    cluster:    debug: 
>> notify_parent: Notifying parent: healthy
>> Aug 09 14:30:20 opensuse150-1 sbd[1078]:  warning: inquisitor_child: 
>> Latency: No liveness for 4 s exceeds threshold of 3 s (healthy servants:
0)
>> 
>> I can think of the way to manipulate quorum with last_man_standing and 
>> potentially also auto_tie_breaker, not to mention 
>> last_man_standing_window would also be a factor... But is there a better 
>> solution?
>> 
> 
> Lack of cluster wide shutdown mode was mentioned more than once on this
> list. I guess the only workaround is to use higher level tools which
> basically simply try to stop cluster on all nodes at once. It is still
> susceptible to race condition.

Are there any concrete plans to implement a clean solution?

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