Hi, I'm looking for a blog post or documentation giving a good overview of the architecture of SolrCloud (not the user experience and use of Solr). The audience would be engineers knowledgeable about distributed systems that know nothing about SolrCloud (side note: I looked for something similar for Elasticsearch and didn't find either).
Documentation that will touch on the index structure (collection/shard/replica), the way they're materialized as cores, the coordination done by ZooKeeper (shard leader élections). How these replicas interact with each other and the update log in steady state and in recovery scenarios. The Overseer role (I wrote the detailed overseer doc https://github.com/apache/solr/blob/main/dev-docs/overseer/overseer.adoc) and how it interacts with ZooKeeper, the storage of all metadata in ZooKeeper, the way nodes start, the way cluster state is propagated and managed (watches for collections with replicas on a node vs all other collection) etc. If anybody knows about a doc that gives a complete overview, I'm very interested. Otherwise might end up writing it 🤓 Thanks, Ilan
