[ClusterLabs] no-quorum-policy=ignore is (Deprecated ) and replaced with other options but not an effective solution

Wed Jun 28 01:38:06 EDT 2023

On Wed, Jun 28, 2023 at 3:30 AM Priyanka Balotra <
priyanka.14balotra at gmail.com> wrote:

> I am using SLES 15 SP4. Is the no-quorum-policy still supported?
>
> Thanks
> Priyanka
>
> On Wed, 28 Jun 2023 at 12:46 AM, Ken Gaillot <kgaillot at redhat.com> wrote:
>
>> On Tue, 2023-06-27 at 22:38 +0530, Priyanka Balotra wrote:
>> > In this case stonith has been configured as a resource,
>> > primitive stonith-sbd stonith:external/sbd
>>
>
Then the error scenario you described looks like everybody lost connection
to the shared-storage. The nodes rebooting then probably rather suicided
instead of reading the poison-pill. And the quorate partition is staying
alive because
it is quorate but not seeing the shared-storage it can't verify that it had
been
able to write the poison-pill which makes the other nodes stay unclean.
But again just guessing ...

> >
>> > For it to be functional properly , the resource needs to be up, which
>> > is only possible if the system is quorate.
>>
>> Pacemaker can use a fence device even if its resource is not active.
>> The resource being active just allows Pacemaker to monitor the device
>> regularly.
>>
>> >
>> > Hence our requirement is to make the system quorate even if one Node
>> > of the cluster is up.
>> > Stonith will then take care of any split-brain scenarios.
>>
>> In that case it sounds like no-quorum-policy=ignore is actually what
>> you want.
>>
>
Still dangerous without something like wait-for-all - right?
With LMS I guess you should have the same effect without having explicitly
specified though.

Klaus

>
>> >
>> > Thanks
>> > Priyanka
>> >
>> > On Tue, Jun 27, 2023 at 9:06 PM Klaus Wenninger <kwenning at redhat.com>
>> > wrote:
>> > >
>> > > On Tue, Jun 27, 2023 at 5:24 PM Andrei Borzenkov <
>> > > arvidjaar at gmail.com> wrote:
>> > > > On 27.06.2023 07:21, Priyanka Balotra wrote:
>> > > > > Hi Andrei,
>> > > > > After this state the system went through some more fencings and
>> > > > we saw the
>> > > > > following state:
>> > > > >
>> > > > > :~ # crm status
>> > > > > Cluster Summary:
>> > > > >    * Stack: corosync
>> > > > >    * Current DC: FILE-2 (version
>> > > > > 2.1.2+20211124.ada5c3b36-150400.2.43-2.1.2+20211124.ada5c3b36)
>> > > > - partition
>> > > > > with quorum
>> > > >
>> > > > It says "partition with quorum" so what exactly is the problem?
>> > >
>> > > I guess the problem is that resources aren't being recovered on
>> > > the nodes in the quorate partition.
>> > > Reason for that is probably that - as Ken was already suggesting -
>> > > fencing isn't
>> > > working properly or fencing-devices used are simply inappropriate
>> > > for the
>> > > purpose (e.g. onboard IPMI).
>> > > The fact that a node is rebooting isn't enough. The node that
>> > > initiated fencing
>> > > has to know that it did actually work. But we're just guessing
>> > > here. Logs should
>> > > show what is actually going on.
>> > >
>> > > Klaus
>> > > > >    * Last updated: Mon Jun 26 12:44:15 2023
>> > > > >    * Last change:  Mon Jun 26 12:41:12 2023 by root via
>> > > > cibadmin on FILE-2
>> > > > >    * 4 nodes configured
>> > > > >    * 11 resource instances configured
>> > > > >
>> > > > > Node List:
>> > > > >    * Node FILE-1: UNCLEAN (offline)
>> > > > >    * Node FILE-4: UNCLEAN (offline)
>> > > > >    * Online: [ FILE-2 ]
>> > > > >    * Online: [ FILE-3 ]
>> > > > >
>> > > > > At this stage FILE-1 and FILE-4 were continuously getting
>> > > > fenced (we have
>> > > > > device based stonith configured but the resource was not up ) .
>> > > > > Two nodes were online and two were offline. So quorum wasn't
>> > > > attained
>> > > > > again.
>> > > > > 1)  For such a scenario we need help to be able to have one
>> > > > cluster live .
>> > > > > 2)  And in cases where only one node of the cluster is up and
>> > > > others are
>> > > > > down we need the resources and cluster to be up .
>> > > > >
>> > > > > Thanks
>> > > > > Priyanka
>> > > > >
>> > > > > On Tue, Jun 27, 2023 at 12:25 AM Andrei Borzenkov <
>> > > > arvidjaar at gmail.com>
>> > > > > wrote:
>> > > > >
>> > > > >> On 26.06.2023 21:14, Priyanka Balotra wrote:
>> > > > >>> Hi All,
>> > > > >>> We are seeing an issue where we replaced no-quorum-
>> > > > policy=ignore with
>> > > > >> other
>> > > > >>> options in corosync.conf order to simulate the same behaviour
>> > > > :
>> > > > >>>
>> > > > >>>
>> > > > >>> *     wait_for_all: 0*
>> > > > >>>
>> > > > >>> *        last_man_standing: 1
>> > > > last_man_standing_window: 20000*
>> > > > >>>
>> > > > >>> There was another property (auto-tie-breaker) tried but
>> > > > couldn't
>> > > > >> configure
>> > > > >>> it as crm did not recognise this property.
>> > > > >>>
>> > > > >>> But even after using these options, we are seeing that system
>> > > > is not
>> > > > >>> quorate if at least half of the nodes are not up.
>> > > > >>>
>> > > > >>> Some properties from crm config are as follows:
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>> *primitive stonith-sbd stonith:external/sbd \        params
>> > > > >>> pcmk_delay_base=5s.*
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>>
>> > > > >>> *.property cib-bootstrap-options: \        have-watchdog=true
>> > > > \
>> > > > >>>
>> > > > >> dc-version="2.1.2+20211124.ada5c3b36-150400.2.43-
>> > > > 2.1.2+20211124.ada5c3b36"
>> > > > >>> \        cluster-infrastructure=corosync \        cluster-
>> > > > name=FILE \
>> > > > >>>     stonith-enabled=true \        stonith-timeout=172 \
>> > > > >>> stonith-action=reboot \        stop-all-resources=false \
>> > > > >>> no-quorum-policy=ignorersc_defaults build-resource-defaults:
>> > > > \
>> > > > >>> resource-stickiness=1rsc_defaults rsc-options: \
>> > > > >>> resource-stickiness=100 \        migration-threshold=3 \
>> > > > >>> failure-timeout=1m \        cluster-recheck-
>> > > > interval=10minop_defaults
>> > > > >>> op-options: \        timeout=600 \        record-
>> > > > pending=true*
>> > > > >>>
>> > > > >>> On a 4-node setup when the whole cluster is brought up
>> > > > together we see
>> > > > >>> error logs like:
>> > > > >>>
>> > > > >>> *2023-06-26T11:35:17.231104+00:00 FILE-1 pacemaker-
>> > > > schedulerd[26359]:
>> > > > >>> warning: Fencing and resource management disabled due to lack
>> > > > of quorum*
>> > > > >>>
>> > > > >>> *2023-06-26T11:35:17.231338+00:00 FILE-1 pacemaker-
>> > > > schedulerd[26359]:
>> > > > >>> warning: Ignoring malformed node_state entry without uname*
>> > > > >>>
>> > > > >>> *2023-06-26T11:35:17.233771+00:00 FILE-1 pacemaker-
>> > > > schedulerd[26359]:
>> > > > >>> warning: Node FILE-2 is unclean!*
>> > > > >>>
>> > > > >>> *2023-06-26T11:35:17.233857+00:00 FILE-1 pacemaker-
>> > > > schedulerd[26359]:
>> > > > >>> warning: Node FILE-3 is unclean!*
>> > > > >>>
>> > > > >>> *2023-06-26T11:35:17.233957+00:00 FILE-1 pacemaker-
>> > > > schedulerd[26359]:
>> > > > >>> warning: Node FILE-4 is unclean!*
>> > > > >>>
>> > > > >>
>> > > > >> According to this output FILE-1 lost connection to three other
>> > > > nodes, in
>> > > > >> which case it cannot be quorate.
>> > > > >>
>> > > > >>>
>> > > > >>> Kindly help correct the configuration to make the system
>> > > > function
>> > > > >> normally
>> > > > >>> with all resources up, even if there is just one node up.
>> > > > >>>
>> > > > >>> Please let me know if any more info is needed.
>> > > > >>>
>> > > > >>> Thanks
>> > > > >>> Priyanka
>> --
>> Ken Gaillot <kgaillot at redhat.com>
>>
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