https://aphyr.com/posts/284-jepsen-mongodb
But it is important to realize that the team at MongoDB has actually been working with Kingsbury, for several years now, and they have slowly and patiently fixed the problems he identified. Consider how the situation had evolved by 2017:
MongoDB 3.4 Passes Jepsen – The Industry’s Toughest Database Test
Jepsen Evaluation Demonstrates MongoDB Data Safety, Correctness & Consistency
On February 7th 2017, Kyle Kingsbury, creator of Jepsen, published the results of his tests against MongoDB 3.41. His conclusions:
"MongoDB has devoted significant resources to improved safety in the past two years, and much of that ground-work is paying off in 3.2 and 3.4. MongoDB 3.4.1 (and the current development release, 3.5.1) currently pass all MongoDB Jepsen tests….These results hold during general network partitions, and the isolated & clock-skewed primary scenario."
https://www.mongodb.com/mongodb-3.4-passes-jepsen-test
MongoDB has become an excellent document-store database. If you are still repeating FUD from 2010, then you are simply out of date. It's time to come up to speed on the reality of 2018.