master_not_discovered_exception ElasticSearch single node

Question

I am trying to setup elasticsearch on a single host. Here is how my configuration looks like:

elasticsearch.yml

node.name: ${HOSTNAME}

network.host: _site_, _local_
http.port: 9200
transport.tcp.port: 9300
cluster.name: "test_cluster"
node.local: true

kibana.yml

server.host: 0.0.0.0
elasticsearch.url: http://localhost:9200

On following command:

curl -XGET 'localhost:9200/_cluster/health?pretty'

I get following message:

{
  "error" : {
  "root_cause" : [
   {
      "type" : "master_not_discovered_exception",
      "reason" : null
   }
  ],
  "type" : "master_not_discovered_exception",
  "reason" : null
},
 "status" : 503
}

In log file I see following message:

not enough master nodes discovered during pinging (found [[]], but needed [-1]), pinging again

Could someone please point me right direction here?

Answer 1

I spent days (sigh) on basically this. I was trying to upgrade my single node cluster from 6.x es to 7.x, and I kept dying on the hill of "master_not_discovered_exception".

What finally solved it for me was examining a completely fresh install of 7.x.

For my single-node cluster, my /etc/elasticsearch/elasticsearch.yml needed the line:

discovery.type: single-node

I hope that saves someone else from spending days like I did. In my defence, I'm very new to es.