Dynamic core creation works in 3.5.0 fails in 3.6.0: At least one core definition required at run-time for Solr 3.6.0?

[Emes, Matthew (US - Irvine)]

Hi:

I have been working on an integration project involving Solr 3.5.0 that
dynamically registers cores as needed at run-time, but does not contain any
cores by default. The current solr.xml configuration file is:-

<?xml version="1.0" encoding="UTF-8" ?>
<solr persistent="false" sharedLib="lib">
  <cores adminPath="/admin/cores"/>
</solr>

This configuration does not include any cores as those are created
dynamically by each application that is using the Solr server. This is
working fine with Solr 3.5.0; the server starts and running web
applications can register a new core using SolrJ CoreAdminRequest and
everything is working correctly. However, I tried to update to Solr 3.6.0
and this configuration fails with a SolrException due to the following code
in CoreContainer.java (lines 171-173):-

if (cores.cores.isEmpty()){
    throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "No cores
were created, please check the logs for errors");
}

This is a change from Solr 3.5.0 which has no such check. I have searched
but cannot find any ticket or notice that this is a planned change in
3.6.0, but before I file a ticket I am asking the community in case this is
an issue that has been discussed and this is a planned direction for Solr.

Thanks,

Matthew