I am looking to add one more node to our existing 2-node ELK cluster running in production.
We're running version 8.1.
I was looking at the elasticsearch documents, for 8.1, it says just to add the cluster name and discovery seed hosts on the new spun up node to add it to the existing cluster.
While with 8.4, it says we can do it via enrolment token.
When I was initially deploying the cluster, I added the second node using the enrolment token which automatically pushed the config in the elasticsearch.yml file on the secondary node and synchronised the config with master node.
I wanted to confirm if I can use the enrolment token method on 8.1 to add the third node to the cluster or do I need to manually make changes in elasticsearch.yml file and copy the certificates.
Also, are there any pre-requisites to be taken care of prior addition of third node as this is a production environment and if something goes bad while adding the new node, it can be rolled back?