Three nodes (not in cluster) - same storage

Elastic Stack Elasticsearch
1

Hello,

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

elastic-design.png1193×1164 25.7 KB

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

2

Are these all in the same datacenter?

3

Yes they are, same datacenter, same vlan.

4

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.

5

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

6

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.

7

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?

8

No, it keeps the data separate.