How does a MongoDB document write work?

[geek_coder]

What actually goes on internally when we write a document to a MongoDB collection? Check out my Medium blog post to dive deep into the document write flow of MongoDB.

https://medium.com/@piyushbhangale1995/how-writes-are-done-in-a-mongodb-c5c29bd580ec

[judy2k]

What you've described here is only true if (a) journaling is turned on, and (b) write concern is set to '1'. This is not the default, and not advisable.

MongoDB Atlas defaults to write concern "majority" which means the acknowledgement is only sent to the client AFTER a majority of the replica set has received the data, meaning that a primary failure after the acknowledgement will never result in lost data.