Swarm Search Feed shows blocked

QUESTION: I have tried to install the Swarm Search (formerly called Indexer) and my new Feed shows as blocked. What could be wrong?

ANSWER: If you configure the feed correctly, and show a node but no shards, that means that the Feed from the Swarm nodes was not successful. The Swarm Search nodes are still waiting for the Swarm cluster to create the index within Elasticsearch.

A likely problem is because the the Swarm Search nodes have iptables running, blocking ports 9200 and 9300.

Check: service iptables status on the Swarm Search nodes to verify those ports are available. Also, verify that Elasticsearch is running: service elasticsearch status