It is indeed good reading, but as you say, old. Since then, we have invested tremendously in the [data replication][0] and [cluster coordination][1] subsystems, to the point that we have closed the issues that Kyle had opened. We have fixed all known issues related to divergence and lost updates of documents, and now have [formal models of our core algorithms][2]. The remaining issue along these lines is that of [dirty reads][3], which we [document][4] and have plans to address (sorry, no timeline, it's a matter of prioritization). Please do check out our [resiliency status page][5] if you're interested in the following these topics more closely.
Thanks for all of the feedback in this entire thread.
[0]: https://github.com/elastic/elasticsearch/issues/10708 [1]: https://github.com/elastic/elasticsearch/issues/32006 [2]: https://github.com/elastic/elasticsearch-formal-models [3]: https://github.com/elastic/elasticsearch/issues/52400 [4]: https://www.elastic.co/guide/en/elasticsearch/reference/7.6/... [5]: https://www.elastic.co/guide/en/elasticsearch/resiliency/cur...
Disclaimer: I am an engineer on the Elasticsearch team; I welcome any and all feedback.