[Pacemaker] Frustrating fun with Pacemaker / CentOS / Apache

[Andrew Beekhof]

On Tue, Feb 16, 2010 at 11:21 PM, Paul Graydon <paul at ehawaii.gov> wrote:
> On 2/16/2010 10:48 AM, Andrew Beekhof wrote:
> Did you try the "cluster- from scratch" doc?
>
>
> Sure, it's the first time things really started to make any form of sense,
> but I'd already struggled through all the other starting and installation
> documents by the time I'd reached that one, which do things a lot
> differently.
> Maybe I'm just being fussy, but it would be awesome if there was just one
> from scratch / starter guide, which really isn't the case.  I (naively?)
> followed the wiki through in the order it pushes you:
>
> http://clusterlabs.org/wiki/Main_Page logically leads you to ->
> http://clusterlabs.org/wiki/Get_Pacemaker  which then leads you on to ->
> http://clusterlabs.org/wiki/Install and from there to ->
> http://clusterlabs.org/wiki/Initial_Configuration and finally I ended up at

Which also tries to send you to the documentation page ;-)
But you have a point, I've made the from scratch doc more prominent now.

I'm also working on a new front page that makes it easier for people
to find this sort of thing.

> http://clusterlabs.org/wiki/Example_configurations
>
> I never even came anywhere close to seeing the documentation list until I'd
> got the cluster half set up, let alone see a link to "cluster from scratch"
> :)  It would be good to put that document up front and center in Install or
> similar to people can see it, or even overhaul the lot with something along
> the same lines but as distro-agnostic as possible?
> I've never seen anyone complain about being too molly-coddled by
> documentation :)
>
> Frankly I'm slightly confused what I've got set up.  "Stack: openais".
> Really?

The core part of openais split off to become corosync.
Not all the docs (or logs) have been updated for this.

>  Did that get installed by corosync and I didn't notice?  Is
> corosync openais?  The FAQ lumps them together so I presume it is, but I
> haven't installed any openais package like was mentioned in the "cluster
> from scratch" doc.  "rpm -qa | grep -i ais" comes up with zip so I'm pretty
> sure it hasn't come in as a separate dependency by surprise!
>
> I'm sorry, this probably comes across fairly harshly and it's not my
> intention, but after a week of grappling with something that should be so
> straightforward, keeping on hitting inconsistencies and differences in
> approach in the different pages without any explanation why, what the
> benefits of each method are etc. etc. just leaves me irritable!  Maybe it's
> stubbornness but I know pacemaker is used in major environments and I'm
> confident it's exactly what we need for our set up.
>
> Whilst I remember one glaring inconsistency between man pages, documentation
> etc. is the bind address in corosync.  Some places say use the network
> address, i.e. end it in .0, others seem to be talking about setting that to
> be the IP address of the server it's on.  Both seem to work, but I've no
> idea what it should be and what the implications of it being set wrong
> are.   I'm inclined to trust "man corosync.conf" which tells you to use the
> .0 network address, over the documentation and examples that don't!

IIRC, I wrote the patch that lets it work with the actual address.
The man page was probably just never updated for this.

Use whatever makes you happy :-)
.0 can make it easier to share configs between machines though.