How to set minimum master node in elasticsearch.yml file?


(ganeshbabu) #1

Running ElasticSearch 1.7 along with Java 7..

So I have a one cluster node with three system and each contains 1 master node,1 data node & 1 client node.

Totally, we will have 9 eligible nodes

My Question is.

How to set minimum master nodes in elasticsearch.yml?

discovery.zen.minimum_master_nodes=?

No.of master nodes= No. of nodes/2+1

number of nodes represent which node?

Thanks,
Ganesh


(Mike Simos) #2

Hi,

Are you saying you have 3 separate cluster? Each has 1 master node, 1 data node and 1 client node? Sorry I am not sure what your configuration is. For "No. of nodes" the only nodes you need to consider is any node which has "node.master: true".


(ganeshbabu) #3

Hi Mike,

No I have only one cluster and has nine nodes.

The formula to calculate no of minimum master nodes is = (no.of nodes/2+1).

My Question is
1.while calculating whether I should consider no of nodes as master, data, client or all nodes in the cluster.
2. How to set and calculate minimum master nodes value in elasticsearch.yml?

Thanks,
Ganesh


(Magnus Bäck) #4

In the N/2+1 formula, N denotes the number of master-eligible nodes. In your case N=1, hence:

discovery.zen.minimum_master_nodes: 1

(ganeshbabu) #5

Thanks for your response.

To set the problem statement right, we have 3 Physical Servers.

Our plan is to setup
a. 3 Master Nodes (1 in each server)
b 3 Client Nodes (1 in each server)
c. 3 Data Nodes (1 in each server)

So, in total, we are planning to have 9 Nodes running from 3 Physical Servers.

Going by the formula, if we consider N as the number of master-eligible nodes (which is 3, in our case),
discovery.zen.minimum_master_nodes: 3/2+1 = 2

Is this a right setting?

Regards,
Ganesh


(Magnus Bäck) #6

And this is the same cluster? Yes, then you have three master-eligible nodes and consequently minimum_master_nodes should be set to two.

Unless these physical servers are very well equipped (e.g. >64 GB RAM) I suspect it's a mistake to run as many ES instances as you're planning.


(ganeshbabu) #7

Yes, ours is highly configured servers with RAM > 64 GB.


(system) #8