On 09/04/25 00:22 -0700, Reid Wahl wrote:
On Wed, Apr 9, 2025 at 12:07 AM Oyvind Albrigtsen <oalbr...@redhat.com> wrote:
On 08/04/25 22:27 +0900, renayama19661...@ybb.ne.jp wrote:
>Hi Reid,
>Hi All,
>
>> > But even going back to those days (late 2012), I don't see any mention
>> > of "nodeid" in the fence-agents repo, which included the fence_scsi
>> > agent.
>
>I also looked into the nodeid parameter, but found nothing.
>Since this was a modification made when unfencing was adopted, I thought that
it might have been made possible to pass the nodeid to the unfencing STONITH
device for key generation, but I could not find any description of this.
It seems like it's probably nodeid from corosync and not related to
fence-agents specifically:
https://github.com/ClusterLabs/fence-agents/issues/270
That would make some sense. But since 2012 the fencer has been looking
for nodeid in the metadata of a fence agent, and reacting accordingly.
I'm not aware of a fence agent that has nodeid in the metadata.
Yeah. The only additional things I can find related to it is
get_node_id() in fence_scsi:
https://github.com/ClusterLabs/fence-agents/blob/main/agents/scsi/fence_scsi.py#L237
and fence-agents commit c9a9dd8d880708539acd36e753e578a5c3a40478 from
2008:
cman: replace high_nodeid with votes in transition message
although the latter changes to votes, but it might indicate that it
was used from cman and RGManager times.
So I guess at some point in time we moved from having to inform
Pacemaker what nodeid it has to the agents getting the info from the
cluster instead.
Oyvind Albrigtsen
Oyvind Albrigtsen
>
>Best Regards,
>Hideo Yamauchi.
>
>> ----- Original Message -----
>>
>> From: "ClusterLabs-ML" <users@clusterlabs.org>
>> To: "Reid Wahl" <nw...@redhat.com>
>> Cc: "Yan Gao" <y...@suse.com>; "ClusterLabs-ML" <users@clusterlabs.org>
>> Date: 2025/04/08 火 19:24
>> Subject: Re: [ClusterLabs] What are RHCS and LHA fence agents?
>>
>>
>> On 2025/4/8 10:44, Reid Wahl wrote:
>> > On Tue, Apr 8, 2025 at 12:15 AM Yan Gao <y...@suse.com> wrote:
>> >>
>> >> Hi Reid,
>> >>
>> >> On 2025/4/8 1:52, Reid Wahl wrote:
>> >>> On Mon, Apr 7, 2025 at 4:30 PM Reid Wahl <nw...@redhat.com> wrote:
>> >>>>
>> >>>> On Mon, Apr 7, 2025 at 4:24 PM Reid Wahl <nw...@redhat.com> wrote:
>> >>>>>
>> >>>>> What are RHCS and LHA fence agents, and what are they used for today?
>> >>>>>
>> >>>>> I would have guessed from the names and what commit messages I've
found that
>> >>>>> * RHCS refers to Red Hat Cluster Suite (a.k.a. cman clusters), which
>> >>>>> has been unsupported since RHEL 7
>> >>>
>> >>> Okay, we really ought to rename this stuff soon. Pacemaker uses the
>> >>> term "rhcs" to mean "standard fence agents" -- the kind that are from
>> >>> the ClusterLabs/fence-agents repository. Pacemaker actually decides
>> >>> "this agent is an RHCS-style agent" if it lives in
>> >>> `PCMK__FENCE_BINDIR` (which is /usr/sbin on my machine) and starts
>> >>> with "fence_".
>> >>>
>> >>> Sigh. Sorry to bother everyone. I'm getting frustrated by unclear and
>> >>> legacy code :)
>> >>>
>> >>>>> * LHA refers to Linux-HA, which... isn't that from Heartbeat clusters
>> >>>>> or something?
>> >>
>> >> Yes, they are originally from heartbeat (the major project by "Linux HA"
>> >> community back then) and now in cluster-glue. Technically they need a
>> >> moderator agent "fence_legacy" to be invoked.
>> >
>> > Interesting, thanks! Do you know whether there's been any movement to
>> > get all of these agents (or equivalent agents) into fence-agents? I
>> > know it's not a trivial task. It just seems odd to me that after this
>> > much time, we haven't at least deprecated the legacy stuff.
>>
>> AFAICS both LHA and RHCS agents might have had a similarly long history
>> :-) Anyway it indeed has been painful to have two different fashions .
>>
>> A good fact is, there are alternatives from fence-agents for the
>> commonly used fencing mechanisms. We are planning on disabling the
>> support for LHA agents with pacemaker-3.0 in the next major release of
>> distribution, meanwhile still need to continue supporting them with
>> pacemaker-2.1 code base though.
>>
>> >
>> >>
>> >>>>>
>> >>>>> All of this is from before my time as a developer for Pacemaker. I'm
>> >>>>> trying to understand what's still relevant and how.
>> >>>>>
>> >>>>> I'm including Yan Gao from SUSE, as they have some commits in the past
>> >>>>> few years related to both agent types.
>> >>>>
>> >>>> Related question: Is anyone aware of ANY fence agent that supports a
>> >>>> "nodeid" parameter? We seem to have some dead code in Pacemaker
>> >>>> related to that. I don't see any agent in fence-agents or cluster-glue
>> >>>> (which is apparently related to LHA fencing) that accepts a nodeid
>> >>>> parameter.
>> >>
>> >> Indeed so.
>> >>
>> >> So-called "Stonith scsi agent support" was mentioned in the PR that
>> >> introduced this:
>> >> https://github.com/ClusterLabs/pacemaker/pull/186
>> >
>> > Also interesting... I didn't find that PR, because when I looked
>> > through `git log`, I found this commit instead:
>> > https://github.com/ClusterLabs/pacemaker/commit/c2265a12
>> >
>> > It's not attached to any PR. These two commits appear to be identical
>> > and both part of the main branch. Odd.
>> >
>> > But even going back to those days (late 2012), I don't see any mention
>> > of "nodeid" in the fence-agents repo, which included the fence_scsi
>> > agent.
>> >
>> > I'm inclined to get rid of the fencer code that automatically adds
>> > this parameter.
>>
>> +1
>>
>> Regards,
>> Yan
>>
>> >
>> >>
>> >> But not sure whether it had anything to do with fence_scsi agent...
>> >>
>> >> Regards,
>> >> Yan
>> >>
>> >>
>> >>>
>> >>> The nodeid question still stands.
>> >>>
>> >>>>
>> >>>> --
>> >>>> Regards,
>> >>>>
>> >>>> Reid Wahl (He/Him)
>> >>>> Senior Software Engineer, Red Hat
>> >>>> RHEL High Availability - Pacemaker
>> >>>
>> >>>
>> >>>
>> >>
>> >
>> >
>>
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--
Regards,
Reid Wahl (He/Him)
Senior Software Engineer, Red Hat
RHEL High Availability - Pacemaker
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