How much clusters must I use in elastic stack?

[sidharth_vijayakumar]

I am confused which approach would be better having single cluster with 12 nodes or having 3 cluster with 4 nodes each in elastic stack. What are the advantages and disadvantages of single cluster? Does elastic charge me for 3 cluster as far as I know they charge for nodes but can someone clarify which would be better approach and which would be cost effective solution?

I am planning to use these nodes in my cluster :

master , data_content, data_hot, ingest, ml, remote_cluster_client

[richcollier]

It depends.

The license tiers are described here:Subscriptions | Elastic Stack Products & Support | Elastic

Since you want to use ML (based on your node type list) - then you will require at least a platinum license.

In general, you can choose whether or not you want to buy node licenses or "capacity-based" licenses. To get "capacity-based" licenses, you need to license at the Enterprise tier, where you buy blocks of ERUs (explained below).

What's the difference?

• In the node model, a licensed node is an instance of the following node types, each of which is up to 64GB in size:
  ** Data nodes
  ** Dedicated Master nodes
  ** Nodes used for cross cluster operations
  ** Dedicated Machine Learning nodes
  Keep in mind that a 1 GB data node is taking up the same license as a 64GB data node. The number of clusters in the node-based model sort of does matter. We'll want to have a separate license for each cluster that's in production (non-prod clusters are not licensed).

• In the "capacity-based" model, an ERU (Enterprise Resource Unit) is defined as block of 64GB of capacity. You are free to create one 64GB node, eight 8GB nodes, sixty-four 1GB nodes, whatever. The number of clusters created also doesn't matter.

In general, despite the fact that an ERU at the Enterprise Tier is more expensive than a node at the Platinum tier, the concept of an ERU allows you much more flexibility and also allows you to use one of our orchestration products to help you manage/deploy clusters (either ECE or ECK)