Adding a new node to existing cluster

[Kamesh_Pratapa]

Hi all,

I have a 5 node elasticsearch cluster (2 client and 3 data nodes,all 3 are master elgible nodes).
The cluster is running in Kubernetes.
Now i wanted to scale the ES cluster which i am adding a new minion node and join the new node to the kubernetes cluster first.

Then currently we are running replication-controller and i will scale the replication controller for ES-data to 4 which a new container instance will be started in my new minion node.Since the cluster name will be the same the new node will be joining to the cluster and data allocation will start automatically ..

My question is

1. Currently we have the variable zen.minimum.Master.Nodes value set to 2.
2. Now when i add a new node i assume i need to change this to 3 as per formula (N/2)+1 which will be 3.
3. Can i do this change using the rest api curl -XPUT -d /_settings/minimum.master.nodes to 3 ?
4. Can i do this once i add the new node and then scale the replicas to 4 so that the new container instance started and new node joined the cluster ?
5. Or i have to do this before adding the node ?
6. Do i need to modify this value in the elasticsearch.yaml files of existing nodes ?

Can you please help me the order of steps to follow ?

Regards,
Kamesh.

[warkolm (Mark Walkom)]

@Kamesh_Pratapa

• Can i do this change using the rest api curl -XPUT -d /_settings/minimum.master.nodes to 3 ?

Yes.

@Kamesh_Pratapa

Can i do this once i add the new node and then scale the replicas to 4 so that the new container instance started and new node joined the cluster ?

Yes.

@Kamesh_Pratapa

Or i have to do this before adding the node ?

Nope.

@Kamesh_Pratapa

Do i need to modify this value in the elasticsearch.yaml files of existing nodes ?

As long as it's set as a persistent setting via the API you should be ok.

@Kamesh_Pratapa

Can you please help me the order of steps to follow ?

What you have looks good.