[Pacemaker] is ccs as racy as it feels?

[Christine Caulfield]

On 11/12/13 00:48, Andrew Beekhof wrote:
>
> On 10 Dec 2013, at 11:31 pm, Brian J. Murrell <brian at interlinx.bc.ca> wrote:
>
>> On Tue, 2013-12-10 at 10:27 +0000, Christine Caulfield wrote:
>>>
>>> Sadly you're not wrong.
>>
>> That's what I was afraid of.
>>
>>> But it's actually no worse than updating
>>> corosync.conf manually,
>>
>> I think it is...
>>
>>> in fact it's pretty much the same thing,
>>
>> Not really.  Updating corosync.conf on any given node means only having
>> to write that file on that node.  There is no cluster-wide
>> synchronization needed
>
> Approximately speaking, cman takes cluster.conf and generates an in-memory corosync.conf equivalent to be passed to corosync.
> So anything that could be done by editing corosync.conf should be possible with 'ccs -f ...', neither command results in any synchronisation or automatic update into the running process.
>
>> and therefore no last-write-wins race so all
>> nodes can do that in parallel.  Plus adding a new node means only having
>> to update the corosync.conf on that new node (and starting up corosync
>> of course) and corosync then does the job of telling it's peers about
>> the new node rather than having to have the administrator go out and
>> touch every node to inform them of the new member.
>
> It sounds like this thread is less about cluster.conf vs. corosync.conf and more about autodiscovery vs. fixed node lists.
>
> Chrissie: is there no way to use cman in autodiscovery mode (ie. with multicast/broadcast and learning about peers as they appear)?
>

Yes,

cman_tool join -X

:-)

Chrissie