I noticed the SolrCloudManager concept added some time ago brought about to abstract away SolrCloud in the context of doing simulated experiments on auto-scaling. Essentially -- need to simulate SolrCloud and not actually use a real SolrCloud. But that need and code went away in 9.0... nonetheless SolrCloudManager and its friends (like DistributedStateManager) are still around. I could imagine someone advocating for them nonetheless. But the present state is very half-implemented as there is code all over the place that assumes ZooKeeper (e.g. uses SolrZkClient or ZkStateReader) instead of some of these abstractions. I think there is a need to set a direction here -- do we embrace abstracting SolrCloud within Solr or do we revert this stuff as needless indirection / concepts.
I think there's lots of room to debate / review the particulars of SolrCloudManager and friends if we do want to keep it. DistributedQueueFactory isn't even used anymore. NodeStateProvider is only for AttributeFactory; not very obvious. DistribStateManager is essentially SolrZkClient but nonetheless still references ZK classes. ~ David Smiley Apache Lucene/Solr Search Developer http://www.linkedin.com/in/davidwsmiley
