* When the schema defines _root_, and you want to do atomic/partial updates...
** _root_ needn't be stored or have docValues any more
** _nest_path_ field isn't needed for this any more
** Simplified internal logic
* Allow (and recommend, eventually insist) that the _root_ field be passed for atomic/partial updates to child docs.
** In the absence of _root_, assume the _route_ param is equivalent to ameliorate back-compat scope. This is a temporary hack; remove in SOLR-15064.
** One of the two is required; you'll get an exception if the assumption is false. THIS IS A BACK-COMPAT CHANGE
* Ensure that the update log contains the _root_ field if it's defined in the schema; in some cases it wasn't. It's important for robustness of atomic/partial updates to child docs. Caveat: the buffer replay scenario is not tested with child docs.
* Limited the cases when a realtime searcher is re-opened. It was being applied to any update that included child docs but now only some narrow subset: only for atomic/partial updates, and when the update log contains an in-place update for the same nest because it's complicated to resolve those log entries.
* Internal improvements to RealTimeGetComponent to aid clarity & robustness & probably performance...
** Use SolrDocumentFetcher.solrDoc(docID, ReturnFields) instead of more manual loading. Will do more with this in another PR.
** Clarify when only root doc IDs are expected.
** Use Resolution enum more, add PARTIAL, remove DOC_WITH_CHILDREN; enhance docs.
** When have ReturnFields, a Set of "onlyTheseFields" becomes redundant. Add a child doc resolution via a transformer when needed.
** Clarified where copy-field targets are removed
* NestPathField should default to single valued, instead of inheriting the schema default, which for ancient schemas was multi-valued.
* AddUpdateCommand.getLuceneDocument(s) methods are very internal; made package visible and refactored a bit for clarity
* DocumentBuilder: when in-place update, skip id and _root_ here, thus also simplifying further logic
* NestedShardedAtomicUpdateTest no longer extends AbstractFullDistribZkTestBase because it wasn't really leveraging the "control client" checking, and it added too much complexity to debug failures.
missing, allBuckets, and numBuckets is not supported with stream method.
So, avoiding picking stream method when any one of them is enabled even if
facet sort is 'index asc'
Adds two metrics to the SolrCloud Overseer: solr_metrics_overseer_stateUpdateQueueSize and solr_metrics_overseer_collectionWorkQueueSize with corresponding entries in the the Prometheus exporter's default/stock configuration.
Co-authored-by: Saatchi Bhalla <s.bhalla@salesforce.com>
* fix some errors in the doc to match reality
* bit more introductory text, and fix the embedded zk port
* add sample image and a tip on directly importing from grafana.com
* per discussion on github issue, this is no longer experimental contrib
