I have Elasticsaerch cluster and want to use Apache Spark to run computations on it. The ES-Hadoop connector contains a Spark library that can run computations on Elasticsearch. Do I have to install Hadoop first or can I just put elasticsearch-spark_2.10-2.2.0-rc1.jar in Spark classpath as documentation mentions in order to make it work?
If you want to use ElasticSearch with Spark then I would suggest you to use Elasticsearch's Spark Native Support.
It is more easy to use and you can directly laod/save data to/from Elastic search as Spark RDD. For more detail refer : Elasticsearch Apache Spark support