I have upgraded from 5.2.1 to a 5.3.2 snapshot -- the lucene_solr_5_3 branch plus the patch for SOLR-6188.
I'm getting errors in my log every time I make a commit on a core. 2015-11-16 20:28:11.554 ERROR (searcherExecutor-82-thread-1-processing-x:sparkinclive) [ x:sparkinclive] o.a.s.c.SolrCore Previous SolrRequestInfo was not closed! req=waitSearcher=true&commit=true&wt=javabin&version=2&softCommit=true 2015-11-16 20:28:11.554 ERROR (searcherExecutor-82-thread-1-processing-x:sparkinclive) [ x:sparkinclive] o.a.s.c.SolrCore prev == info : false 2015-11-16 20:28:11.554 INFO (searcherExecutor-82-thread-1-processing-x:sparkinclive) [ x:sparkinclive] o.a.s.c.S.Request [sparkinclive] webapp=null path=null params={sort=post_date+desc&event=newSearcher&q=*:*&distrib=false&qt=/lbcheck&rows=1} hits=459866 status=0 QTime=0 2015-11-16 20:28:11.554 INFO (searcherExecutor-82-thread-1-processing-x:sparkinclive) [ x:sparkinclive] o.a.s.c.SolrCore QuerySenderListener done. This core has been optimized several times since the upgrade, so there are no longer any segments built by 5.2.1. Is this a problem? I found the code that generates the errors. It says it is a temporary sanity check, that it can be changed to only an assert in the future -- an assert that currently would fail. The fact that whoever wrote the code chose to log at ERROR has me a little worried. I'm completely rebuilding one of the indexes handled by this server, to see whether this error still happens on an index built from scratch. It has several more hours before it will be ready. Thanks, Shawn