Why does ShardHandler exist? It lacks javadocs (as do most classes; shame!) so I'm left to make guesses. I'll make a straw-man claim here: a SolrClient should be enough in most cases, maybe all cases with more work. ShardHandler appears very async-centric (submit then call a different method to collect a response). Http2SolrClient in particular has an asyncRequest method for that use-case. By its name and my recollection of its original and sole use (to search shards / distributed-search), I believe this thing has been over-used for many other things in Solr for Solr-to-Solr communication.
~ David Smiley Apache Lucene/Solr Search Developer http://www.linkedin.com/in/davidwsmiley
