Is there a way to bypass that, and to use singletons in a "singleton" fashion between cores? Btw: Cores do see MultiCore as a singleton, i.e. all handler see the same object, so I could get around this problem using MultiCore to get cores..., but I would like to understand why cores doesn't seems to share singletons. I may be wrong, but this used to work with (old) Henri's solr215 patch.
I don't totally understand what issue you are having. What is the specific function call that is not behaving how you would hope?
Is it that: private static SolrCore instance; is not really a singleton? and that SolrCore.getSolrCore() returns the last SolrCore initalized rather then the first one?
My thinking with this is that the 'instance' variable is @Deprecated and should go away (along with getSolrCore). Any requests to get a SolrCore should be made with the real singleton class MultiCore -- that seems cleaner then adding a static registry to SolrCore.
Is that what you are refering to? ryan
