[arafalov]

You can use embedded Lucene if you want great search but no UI/schema management and you are happy to code the integration. You can start with 3 jars (5Mb) in size and add additional jars as your needs expand (e.g. multilingual processing).

You can use a single node Solr, if you want UI and send data in multiple formats and may eventually need to scale.

You can use Elasticsearch if you know you are starting big and deal with scaling from the start.

You have the choice. It is not just clustered Elasticsearch vs code your own.