configuring shard handler at a more 'global' level?

[Shawn Heisey <so...@elyograg.org>]

SOLR-3221 added the ability to configure the shard handler in Solr.   In
particular, increasing maxConnectionsPerHost is important for
scalability, and many people might want to enable fairnessPolicy.

http://wiki.apache.org/solr/SolrConfigXml#Configuration_of_Shard_Handlers_for_Distributed_searches

What I'm wondering is whether there might be a more global way to
configure this, so it doesn't need to be done on every request handler.
 Ideally, it would be possible to configure this in one place for all
cores, but a config option for every core (solrconfig.xml) would work too.

Does each request handler get its own HttpClient, or is there one per
core?  I know there is one HttpClient per HttpShardHandlerFactory and
all HttpShardHandler instances generated by that factory share the
HttpClient.  I don't know if there's one factory per handler, or one
factory per core.

Side note: Java seems to have a really odd idea of what "fair" means
when it comes to a queue.  In other contexts, you have a choice between
FIFO, fair, and others.  With java, fair seems to mean FIFO.

http://en.wikipedia.org/wiki/Fair_queuing
http://docs.oracle.com/javase/6/docs/api/java/util/concurrent/SynchronousQueue.html#SynchronousQueue%28boolean%29

Thanks,
Shawn