We have just started seeing an intermittent problem in our production Solr instances, where the same document is returned twice in one request. Most of the content of the response consists of duplicates. It's not consistent; maybe 1/3 of the time this is happening and the rest of the time, one return document is sent per actual Solr document.
We recently made some changes to our caching strategy, basically to increase the values across the board. This is the only change to our Solr instance for quite some time. Our production system consists of the following: * 'write', a Solr server used as the master index, optimized for writes. all 3 application servers use this * 'read1' & 'read2', Solr servers optimized for reads, which synch from the master every 20 minutes. these two are behind a pound load balancer. Two application servers use these for searching. * 'read3', a Solr server identical to read1 & read2, but which is not load balanced, and used by only one application server. Has anyone any ideas how to start debugging this? What information should I be looking for that could shed some light on this? Thanks for any advice, Rachel