Three nodes (not in cluster) - same storage


I'm trying to understand something, which is still unclear to me.
Check the design below

I would like to know if it is possible a Loadbalancer to send requests to elastic node 1, which is a primary node and elastic node 2 which is a disaster recovery node to share the same set of documents, which are placed in a single folder on the shared storage?

If this is not possible, why?

In such situation, can I have a third node - a replica for queries that are 3 months old and more?

Thanks in advance

Are these all in the same datacenter?

Yes they are, same datacenter, same vlan.

You can do this, but it may be slow due to the shared storage aspect.

Also take a look at shadow replicas, they may be useful.

By shared storage I meant the same folder for indexes for both of the nodes. Is it achievable?

Sort of.

You can use, eg, /mount/elasticsearch/data and point both nodes to it. Then ES will automatically create a subdirectory with the name of the cluster and then each node will create it's own directory under that.
You will end up with something like /mount/elasticsearch/data/clustername/nodes/0 and /mount/elasticsearch/data/clustername/nodes/1.

But this does mean that I will store the same data twice on different folders. I mean can they both use /mount/elasticsearch/data/clustername/nodes/0 lets say?

No, it keeps the data separate.