[Pacemaker] newbie question(s)

Digimer lists at alteeve.ca
Fri May 24 18:11:11 UTC 2013


On 05/24/2013 01:30 PM, Lars Marowsky-Bree wrote:
> On 2013-05-24T12:15:04, Digimer <lists at alteeve.ca> wrote:
>
>> Nope. Until RHEL 5, openais was the communication layer of the cluster.
>> However, the full AIS API was deemed "overkill" for what HA clustering
>> needed, so corosync was created for RHEL 6 as a stripped-down, HA focused
>> version of openais. In turn, openais was made a corosync plugin for those
>> who actually want the full AIS API.
>
> You know, there *is* a software community out there that doesn't use
> RHEL. Really. ;-) At the time, this was actually a community decision
> and not RHEL-driven. (Though of course the needs of RHEL also informed
> it.)

You are absolutely correct. However, I can only speak to what I know.

/me puts on her crimson fedora :)

> The AIS APIs were mostly just not deemed worth the trouble. Outside a
> very narrow field (Carrier Grade), very few people used them, and those
> that did preferred the opensaf implementation. Hence, openais turned out
> to not be worth the effort of long-term support for a rather complex set
> of services and a *huge* specification.
>
> OCFS2 and cLVM2 exist in an incarnation that uses the AIS CKPT
> (checkpoint) service for synchronization, but that has been/will be
> rewritten too.
>
>> The concepts of "Active/Active", "Active/Passive", etc. is not a membership
>> or cluster communication layer question. Those concepts come from the
>> resource manager (rgmanager or pacemaker).
>
> Yes - and no, because it neglects the detail that the AIS stuff does
> include the notion of a limited cluster manager too.
>
> Regards,
>      Lars

Yes, again right, but it seemed far enough out of scope to not 
mention/confuse the topic. it's not practical in the open source HA 
space, so far as I have ever seen.

-- 
Digimer
Papers and Projects: https://alteeve.ca/w/
What if the cure for cancer is trapped in the mind of a person without 
access to education?




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