Getting exception from /solr/admin/metrics

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

I had never seen the /solr/admin/metrics endpoint, so I tried to access
it on my dev server.  It threw an exception.  This is the first line:

2017-09-1414:27:11.629ERROR
(qtp1394336709-480905)[]o.a.s.h.RequestHandlerBaseorg.apache.lucene.store.AlreadyClosedException:Alreadyclosed

The rest of the log information directly pertaining to this issue is
available here for the next month:

https://apaste.info/aXOm

There isn't anything that *I* would consider to be particularly unusual
about the setup.  The version is 6.6.0.  I do have a third-party plugin
installed, and some update processors that I've written myself.  I have
no idea whether those could have caused this problem, but I think it's
unlikely.

The message does not say what index directory was being accessed when
the problem occurred.

I tried to use the branch_6_6 code so I could add the path to the index
directory to the exception message, but with the generated
6.6.2-SNAPSHOT package, I couldn't get Solr to start properly.  Some of
my cores failed to initialize, and the logs are very unclear on what
went wrong.  Switching the service symlink back to 6.6.0 allowed
everything to start correctly.  I may need to check out the 6.6.0 source
tag and modify that instead of trying to upgrade.

Thanks,
Shawn