Is it a good idea to put an L4 load balancer in front of three physical servers?

OpenSearch
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Hi All,

I have three servers, with each server running one cluster-manager node and three data nodes

“I am wondering if it is a good idea to place a Load Balancer (LB) in front of an OpenSearch cluster that is configured for high availability (HA). I am having trouble finding relevant documentation, so I am asking here.”

Any advice would be greatly appreciated.

Thanks in advance!

2

@floodbin Using LB in front of OS cluster is actually a common pattern, as long as it front HTTP interface only. The transport (9300) should be left untouched as the nodes should be able to communicate with each other directly.

Just to elaborate, the HA is already achieved by having 3 cluster manager nodes, together with primary and replica shards.

The LB used for HTTP traffic:

  • provides one stable endpoint, like https://search.example.com:9200 instead of teaching all clients about all node IPs.
  • Useful if you have clients you don’t fully control (3rd-party tools, SaaS connectors, etc.) that only support a single host.
  • provides obfuscation of internal topology (node IPs/hostnames) behind one virtual IP
  • Used for other use cases like firewalls, network-level policies etc.

Hope this helps