For the seventh edition of the Mozilla sysadmin days, Fred gave a talk about Running & Scaling Large Elasticsearch Clusters at Synthesio.
Less than an hour of all the cases that you may encounter as part of the management of a (more or less) big Elasticsearch clusters, the main pitfalls and how to avoid them.
It assumes that you know the basics of Elasticsearch and Lucene in order grasp all the interesing parts.
Notes: slides are in english but talks are in french