For one question I can reply to myself about actionGet(), it seems that execute() returns and ActionFuture which has actionGet() (cf : http://www.thelastcitadel.com/lab/elasticsearch/javadoc/org/elasticsearch/action/support/AdapterActionFuture.html#actionGet%28%29) which is related to java's Future which has a get() http://download.oracle.com/javase/1,5.0/docs/api/java/util/concurrent/Future.html#get%28%29 used to wait for the asynchronous operation to finish.