Elasticsearch vs Cassandra vs Elasticsearch with Cassandra

Question

I am learning NoSQL and looking at different options for one of my client\'s requirements. I have gone through various resources before putting up this question (a person w

Answer 1

Cassandra is great at retrieving data by ID. I don't know much about secondary index performance, but I doubt it's as fast as Elasticsearch. Certainly Elasticsearch wins when it comes to full text search functionality (text analysis, relevancy scoring, etc).

Cassandra wins on update performance, too. Elasticsearch supports updates, but an update is really a reindex + soft delete in an atomic operation.

Cassandra has a very nice replication model (if you need to be extra-fail-safe). Elasticsearch is OK, too, I'm not in the camp that says ES is particularly unreliable (it has issues sometimes, like all software).

Elasticsearch also has aggregations for real-time analytics. And because searches are so fast, analytics on a subset of data will be fast, too.

If your requirements are satisfied well enough by one of them (like here it seems like ES would work well), I would just use one. If you have requirements from both worlds, then you can either:

• use one of them and work around the downsides. For example, you may be able to handle many updates with Elasticsearch, but with more shards and more hardware
• use both and make sure they're in sync