I'm seeing the same behavior. The CoreAdminAPI call (as generated by the Admin UI) looks correct, and the core.properties file is removed.
I don't see anything in the CHANGES.txt for this release which would imply such a change in behavior, nor anything in the 6.6 reference guide, so it looks like a bug. -Simon On Fri, Jun 9, 2017 at 5:14 AM, Andreas Hubold <andreas.hub...@coremedia.com > wrote: > Hi, > > I just tried to update from Solr 6.5.1 to Solr 6.6.0 and observed a > changed behaviour with regard to unloading cores in Solr standalone mode. > > After unloading a core using the CoreAdmin API (e.g. via Admin UI), I > still get search results for that core. It seems, the search request > triggers automatic recreation of the core now. With Solr 6.5.1 search > requests to unloaded cores were answered with 404 as expected. > > Can you confirm this being a bug in 6.6.0 or is this an intended change? > > Cheers, > Andreas > >