[rabbitmq-discuss] Adding new nodes to a cluster

[Sammy Yu]

Hi guys,
   I've getting my rabbitmq cluster setup.  I noticed in the
documentation there was reference to two different kinds of nodes, a
ram and disk node and it seems to infer that there can only be one ram
node and N disk nodes.  My understanding is that the ram node has no
persistent information about the other nodes whereas the disk node
does.  What's the reasoning behind the constraint and why is it it
necessary to have a ram node (I'm assuming there are some performance
implications)?   Also is it true that the output of the first node
listed in rabbitmqctl status is the ram node?  So given the following
output:
 {nodes,[rabbit at rabbit1,rabbit at rabbit2,rabbit at rabbit3]},
We can assume that rabbit1 is the ram node and rabbit2 and rabbit3 are
disk nodes.

Thanks,
Sammy