Unable to join 2 nodes on CB-2.0

Adding node 10.124.150.181 to 10.120.217.124.

On node 10.124.150.181, there is no memcached process running, there are no cores available as well.
This is not always reproducible.

Attaching the diags from both these nodes.

Add transaction of 'ns_1@10.124.150.181' failed because of {error,
complete_join,
<<"Join completion call failed. Failed to start ns_server cluster processes back. Logs might have more details.">>,
{error,
rest_error,
<<"Failed to start ns_server cluster processes back. Logs might have more details.">>,

{client_error, [<<"Failed to start ns_server cluster processes back. Logs might have more details.">>]}

}}