[ClusterLabs] Simple Clarification's regarding pacemaker

[RaSca]

Il 26/04/2016 13:39, K Aravind ha scritto:
> Hi all 
> Have some doubts regarding pacemaker 
> It would be of great help if you could help me out
> 
> 1.Pacemaker handles split brains using quorum and stonith only right .? 
>   It is not a case where a split brain is resolved wothout the use of
> stonith and qourm am  I right ? 

Not by default. But if you set no-quorum-policy according to what you
want to achieve you may obtain something similar to a split brain
resolution.

> 2.Resource stickiness /location cannot be used to solve split brain right ?

Again, it depends. For example if you set a location based upon the
network connectivity, then you may obtain that a disconnected node will
not run any resource.
That said if you want to be 100% sure you must use stonith.

> 3.let's say I have qourum enabled but not stonith for a two node cluster
> ..can it be used for solving split brain ..if so can the user
> application can add rules for quorum to elect appropriate / preffered
>  the master ..similar to resource stickiness ?

Again, see no-quorum-policy.

> 4.can I configure the default role for a node ? 
> Meaning ...let's say I have a two node master slave setup 
> ,master node goes down and the slave is elected as a master so far so
> good now let's say the older master which was down comes up. So is there
> a way I can configure it be slave by default meaning whenever a new node
> comes up it be a slave and not a master

You can work on default resource stickiness to INFINITY in this case.

> 5.Can I have node roles other than master or slave in a master slave
> cluster say unknown ?

No, AFAIK.

> 6.Is there notification from pacemaker when a split brain happens ,
> When an election beings ,
> When an election is done
> Thanks
> Aravind

Just in the logs, but you can setup something like email notification
for each action. I don't know how things are now, but in the past those
were a lot of mail (and when I say a lot I mean a LOT).

Bye,

-- 
RaSca
rasca at miamammausalinux.org
http://www.miamammausalinux.org