For most use-cases (indexing denormalised data as documents then running searches against them), there's little difference between the two. The mechanics of how the cluster operates are almost identical.
There are some Elasticsearch features that were part of X-Pack (their commercial offering) so aren't included in the OpenSearch fork. Some of those features are really nice to have and make life much easier; the enrich ingest processor is something I really miss in OpenSearch.
The biggest differences are in the tooling around Elasticsearch. All the observability stuff, the SIEM features, various integrations, and now the AI fluff. I've worked with clients in different sectors and - aside from the observability stuff (which is really nice) - none have had an appetite for any of that.
The OpenSearch team is doing some really cool stuff and the project has come a long way. I'm sure it'll continue to improve. It has a very loyal customer base and even has its own annual event; OpenSearchCon 2024 is next month!
There are some Elasticsearch features that were part of X-Pack (their commercial offering) so aren't included in the OpenSearch fork. Some of those features are really nice to have and make life much easier; the enrich ingest processor is something I really miss in OpenSearch.
The biggest differences are in the tooling around Elasticsearch. All the observability stuff, the SIEM features, various integrations, and now the AI fluff. I've worked with clients in different sectors and - aside from the observability stuff (which is really nice) - none have had an appetite for any of that.
The OpenSearch team is doing some really cool stuff and the project has come a long way. I'm sure it'll continue to improve. It has a very loyal customer base and even has its own annual event; OpenSearchCon 2024 is next month!