getting error while starting memecached service with ndb engine
Make sure that you have at least 2 unused API slots ([mysqld] sections) in your configi.ini file (and perform a rolling restart of your Cluster after adding them). These slots will then be used by memcached.

Note that you can choose to run mysqld processes on the host as well and have them part of the cluster (can access the same data through SQL and NoSQL) - you just need to make sure that you include enough [mysqld] sections in your config.ini file so that there are a couple left for memcached.