I am facing issue of cluster health as yellow becasu of some unassign shared

Elastic Stack Elasticsearch
1 
{
    "cluster_name": "app_search",
    "status": "yellow",
    "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": 5,
    "delayed_unassigned_shards": 0,
    "number_of_pending_tasks": 0,
    "number_of_in_flight_fetch": 0
}

i tried with below approach

1)my cluster health was red then i have deleted data folder then cluster health became green after that i have created mapping it's turned to yellow, so if i am missing anything please help me out on this.

2

So are you asking for assistance here, or just telling us your cluster is yellow?

3

My guess is that you defined the number of replicas to 2.

4

Thanks for your replay, Yes David , I have define index.number_of_replicas:2 is it ok or not

5

So everything is correct here.

You have 5 primary shards + 2 copies of each which means 15 shards to allocate.

On a 2 nodes cluster, you will end up with

  • 5 primary shards
  • 5 replica shards

If you add a new node you will allocate:

  • 5 primary shards
  • 5 replica shards
  • 5 replica shards
6

thanks for your response David.

if everything seems correct, does this mean cluster health yellow will not make any problem in future ?

7

The question is "why did you change the number of replicas?".

I won't keep a yellow cluster in production.
If a node stops, you won't be able to index new data because of the quorum.

So if you want to have only 2 data nodes, keep number of replicas to 1.
But in any case add a 3rd node to avoid split brain issue. Can be a master only node which will act as a tie breaker.

8

Thanks for your response David , I am New to Elastic Search, How can I change cluster health yellow to green is there any way to do that.

9

If you are new to elasticsearch, why did you change the replica settings?

Change that. Read: https://www.elastic.co/guide/en/elasticsearch/reference/2.3/indices-update-settings.html

10

Hi David, I have 3 server's i need to sync the data of this 3 server's how can i do in elasticsearch(cluster name and index name is same in all server's,in every server i have install elasticsearch separately )

Example:10.141.4.221 is Load Balancing it's have 3 server's (10.141.2.2,10.141.2.3,10.142.2.4) cluster and index name is same in all server's