This was nginx because I haven’t configured it for elastic search. It was done for sync gateway only. But for experiments I did tried Elastic search on it. So I removed Nginx and disabled firewall. And the cluster reference was created.
@atom_yang I was using the same guide you suggested. But now in create replication mode I am stuck again. And there is a bug reported for it.
Following is the discussion for the same :-
The issue logged @ https://github.com/couchbaselabs/elasticsearch-transport-couchbase/issues/144
Is it possible to have a work around by installing a couch base 4.0 cluster and replicate that with main cluster and then link that with elastic search.