Elasticsearch¶

Disable auto-discovery¶

To prevent Elasticsearch from auto-discovering other nodes on the network, add the following to /etc/elasticsearch/config/elasticsearch.yml

node.local: true # disable network

Check cluster health¶

See: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/cluster-health.html

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

Sample output:

{
  "cluster_name" : "testcluster",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 2,
  "number_of_data_nodes" : 2,
  "active_primary_shards" : 5,
  "active_shards" : 10,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0
}

Find problem shards¶

If the Cluster health returns as “red” or “yellow” you can find problem shards with:

curl -XGET 'http://localhost:9200/_cluster/health/?level=shards&pretty=true'

You can redirect the STDOUT to a text file and search for “red” or “yellow” to find the problem indexes/shards.

Cluster health is yellow¶

If Cluster health returns as yellow, it “means that the primary shard is allocated but replicas are not” [1]. This often means that you have do not have enough ES nodes in your cluster to support the desired number of replicas of an index. This happens when you have indexes with ‘number_of_replicas’ > (the number of ES nodes you are running - 1). For instance if you only have 1 ES node, number_of_replicas should be set to 0. To reduce (or increase) the number of replicas on an existing index, you can use:

curl -XPUT 'localhost:9200/my_index/_settings' -d '
{
    "index" : {
        "number_of_replicas" : 0
   }
}

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