Thank you all, Actually, "the documents" i mentioned in my question, was a talk
in youtube seen long time ago and could not find it. Also noticing that a lot
of companies like Netflix built hundreds of Clusters each having 10s of nodes
and saying that its much stable, i just concluded that big cluster is not
recommended. I see some of the reasons in your answers: the problem with
dynamic snitch and probability of node failures that simply increases with more
nodes in cluster which even could cause cluster outage.
