How to fix cluster health yellow with Elastic Search

Question

I have setup on server, with MongoDb and ElasticSearch. Using https://github.com/richardwilly98/elasticsearch-river-mongodb I have connected ElasticSearch and MongoDb together.<

Answer 1

Looks like you don't have a node for replica shards to go to. You can lower your replica count to 0 or add a second node to your cluster so that primary and replica shards can be safely placed on different nodes.

The default configuration in elasticsearch.yml is probably this:

index.number_of_shards: 5  
index.number_of_replicas: 1

The idea being that if your node crashes, another node in your cluster will have a copy of the shard. Since you only have one node, the cluster has no idea where to put the replicas and thus is in a yellow state.