Tips on Configuring Elasticsearch for High Performance

Also if you often only search a part of your DB (e.g. Search the Posts of one user/group), use routing. In other DB also known as Partitioning.

http://www.elasticsearch.org/guide/en/elasticsearch/referenc...

Here is another set of notes which helped me improve my cluster configuration [0].

[0] http://gibrown.wordpress.com/2013/01/24/elasticsearch-five-t...

#3 was especially poignant. The first time I encountered the 'split brain' problem i was left scratching my head for a while.

For beginners, I cannot recommend this tip highly enough:

"action.disable_delete_all_indices: true"

Protection, protection.

(from an actual victim who learned the hard way ;-(