I have considered the server from where I control remote databases as leader and others as remote servers. The 'monetdb discover' in the leader is not showing any other database(except self dbs).
I have enabled discovery and control properties in the remote servers. What other configurations are needed for successful discovery in EC2 environment?
MonetDB cluster enables mclient to combine all the (select)query results from remote servers and itself. The application should take care of shared write into nodes.