We have a longstanding issue with "failed to respond" errors in Solr when our coordinator is querying our Solr shards.
To elaborate further... we're using the built-in distributed capabilities of Solr 3.6, and using Jetty as our server. Occasionally, we will have a query fail due to an error like "org.apache.commons.httpclient.NoHttpResponseException: The server solr-shard-13 failed to respond" when the Solr coordinator is sending a request to one of its shards. Over the long term, this happens for about 1 out of 3000 queries. The quick fix of simply retrying the query when such an intermittent error occurs works fine, but I'm trying to figure out what the root cause might be. I've got lots of theories and possible fixes, but was hoping someone had run into this before and knows the answer straight away :) -Michael
