[Openais] Order of membership lists.

[Christine Caulfield]

Alan Conway wrote:
> Are the membership lists passed to the callback cpg_confchg_fn_t and
> retruned by cpg_membership_get guaranteed to be in any particular order,
> e.g. youngest to oldest?
> 
> If not, are all members of the cluster guaranteed to get the membership
> list in the same order?

No. the node/pid list will not necessarily be in the same order on all 
nodes. Even though the join/leave mechanism is strictly ordered, when 
new nodes are added to a group they get their list sent to them from 
other nodes and this will arrive after they have added themselves.

> I'm looking for a way to pick a single member of the cluster to respond
> to config changes - e.g. to mcast cluster-wide information for new
> members.

The usual way of doing this is to pick the lowest node ID of all nodes 
in the group.

-- 

Chrissie