To check on elasticsearch cluster health you need to use
curl localhost:9200/_cat/health
More on the cat APIs here.
I usually use elasticsearch-head plugin to visualize that.
You can find it’s github project here.
It’s easy to install sudo $ES_HOME/bin/plugin -i mobz/elasticsearch-head
and then you can open localhost:9200/_plugin/head/ in your web brower.
You should have something that looks like this :
