5.0 finally has the ability to tell the API (with the refresh=waitfor parameter) to wait until a change is made visible in the index — which up to now has been a challenge with any use case that needs causal consistency.

As far as I can tell, ES still doesn't offer an API to let the client query about the visibility status themselves, but this is good enough.

Key changes:

* Faster indexing

* Ingest node

* New scripting language (called Painless)

* New data structures from Lucene

* Instant Aggregation

* TF/IDF -> BM25 to calculate relevance

* Fail faster philosophy

* a low level Java HTTP/REST client

Congratulations on shipping 5.0.0!

I am still sad though that Elasticsearch continues to operate but RethinkDB shut down. Just shows, business is just as important as tech.

I think people overestimated the coolness of the tech of rethinkdb (especially comparing to es).

IPv6 data type - finally :)

Implementing grok directly on the ingress is a nice touch as well.