[Samba] Do you NEED pacemaker when using Samba Clustering (ctdb)

[Martin Schwenke]

Hi John,

On Sat, 12 Nov 2022 21:13:52 +0000, John Ericsson via samba
<samba at lists.samba.org> wrote:

> I have used a two-node active-active samba cluster using cstb (using
> clustered filesystem) and it has been working fine for over 3 years.
> I set up a test environment and configured the samba using ctdb and forgot
> to turn on pacemaker. Thing is it all works fine even without pacemaker.
> Thinking about it ... of course it does, it works as the samba team said it
> works. I should have asked this question 3 years ago. .
> So what is pacemaker brining to the party when I read stuff like
> "The current implementation of the CTDB Resource Agent configures CTDB to
> only manage Samba. Everything else, including IP failover, should be
> configured with Pacemaker."

I think you have answered your own question.  I am a current CTDB
developer, but I don't know enough about the current state of Pacemaker
to be able to say where it might do better than CTDB's IP failover. 

So, I guess it depends on the experience and motivations of whoever
wrote that.  They may have encountered situations where CTDB's IP
failover didn't meet their requirements.  If that's the case then it
would have been nice to hear about it so we could improve CTDB.  😉️

Note that we have been talking about a CTDB rewrite for quite a few
years.  The idea would be to split CTDB into neat, logical components,
without throwing away existing functionality.  The would be an
improvement over CTDB's current monolithic design/implementation.  If
we achieve this then perhaps it will be possible to replace some
components with 3rd party components like Pacemaker. This is somewhat
possible at the moment (obviously, since someone recommends using
Pacemaker instead of CTDB's IP failover) but there is no way of
completely switching off CTDB's failover code, because doing that was
never intended.

> I appreciate that there is no STONITH options.

Support could be added to CTDB...

peace & happiness,
martin