[Pacemaker] Announce: pcs / pcs-gui (Pacemaker/Corosync Configuration System)

[Andrew Beekhof]

On Tue, Jun 5, 2012 at 9:27 PM, Lars Marowsky-Bree <lmb at suse.com> wrote:
> On 2012-06-05T09:43:09, Andrew Beekhof <andrew at beekhof.net> wrote:
>
> Hi Andrew,
>
>> > (When we're talking about Pacemaker (versus the crm), it is obvious that
>> > that wasn't really a technology-driven move.)
>> With the implication being that technology-driven moves are bad?
>> How do you explain HAWK then? Shouldn't Tim have written a patch to
>> py-gui instead?
>
> The python-UI was an entirely different architecture to hawk.

Apparently PCS (GUI and cli) can or will make REST calls to
setup/query/control machines from outside the cluster.
The last time I looked, the shell wasn't intended to operate remotely.

Just that and skipping the bi-directional XML translation already make
both pretty different beasts under the covers.
How you'd non-trivially achieve both in a single project would be
interesting to see.

> That's not
> even apples to oranges, that's apples to a horse ;-) We *did* worry a
> bit between hawk and looking at drbd-mc though, but even there (the
> reasonably heavy-weight java client and the implications of it) the
> architecture was significantly different.
>
> Obviously, not all technology-driven moves are bad.
>
> And I think the elephant in the room that we're all too polite to
> mention here is that technology probably only accounts for about half of
> the rationale.

Since Chris was the one most affected, he also did the evaluation and
made the decision.
No elephants here.

>
>> > Of course. Still, people will ask "which one should I choose", and we
>> > need to be able to answer that.
>>
>> The same way the Linux community has answers for:
>> - sh/bash/tsch/zsh/dash...
>> - gnome/kde/enlightnment/twm/fvwm...
>> - fedora/opensuse/debian/ubuntu/leaf...
>> - mysql/postgres/oracle/sybase
>> - ext2,3,4/reiserfs/btrfs...
>> - GFS2/OCFS2
>> - dm_replicator/drbd
>> - selinux/apparmor
>> - iscsi clients
>> - chat/irc/email clients
>> - programming languages
>> - editors
>> - pacemaker GUIs
>>
>> Linux is hardly a bastion of "there can be only one", so I find the
>> level of doom people are expressing over a new cli to be disingenuous.
>
> Don't get me started. There's quite a few examples in your list where
> I'd be more than willing to ask "Why, pray tell, WHY" too. ;-) (Just
> look at the cost we pay for something as trivial as slightly
> incompatible Unix shells in the resource agents ...) There is always a
> cost to choice, which is why it is a very valid question to ask if we
> need the choice, and what we gain from it.
>
>> Every argument made so far applies equally to HAWK and the Linbit GUI,
>> yet there was no outcry when they were announced.
>
> No, like I said above, that did suck - but the architecture truly is
> different and drbd-mc just wasn't the right answer for customers who
> wanted a HTML-only frontend. Besides, this is not an outcry. An outcry
> is revoking people's mailing list privileges and posting angry blogs.
> ;-)
>
>> It seems duplication is only bad to those that aren't responsible for it.
>
> No, it is actually only bad for people who are responsible for
> maintaining it.

So don't?  Just copy any good ideas that come along.
Assuming they're architecturally compatible.

>
> And there's always a balance to be struck between unification &
> convergence and exploring new paths. I'm not even saying "Don't go
> there!" (because I am perfectly well aware I can't stop anyone), I'm
> still mostly working out how that new path differs from the existing
> one.
>
>> Presumably you'll continue to advise SLES customers to use whatever
>> you ship there.
>> Doesn't seem too complex to me.
>
> You do know it isn't that simple. "But distro X does Y, we want that on
> your's too!" "Why are you doing Z?" And of course there's the question
> of *what to ship*, for which someone, somewhere needs to have a remotely
> informed opinion ;-)
>
>
> Regards,
>    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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