Mongo error after migrating to Atlas

Doing a compulsory migration to Atlas, due to the buyout of mlab. My app now crashes with this error - any help appreciated.

MongoError: Cannot use (or request) retryable writes with limit=0
at Function.MongoError.create (/Users/me/.meteor/packages/npm-mongo/.
at toError (/Users/me/.meteor/packages/npm-mongo/.
at /Users/me/.meteor/packages/npm-mongo/.
at handler (/Users/me/.meteor/packages/npm-mongo/.
at /Users/me/.meteor/packages/npm-mongo/.

I can just tell you that Atlas has been cake to configure with multiple Meteor projects/apps for me.

I’ve not done a migration before, but maybe you could create a new empty Meteor app & connect Atlas to make sure you’ve got the basics down.

Then take what you learn from there and apply it to your current project. Atlas runs 3 node clusters as a minimum configuration, so you can set a “write concern”:

Also MongoDB 4.0+ requires you to set Retryable Writes to true

This error suggests to me that you might have some issues with your write configurations:

MongoError: Cannot use (or request) retryable writes with limit=0

Here is a helpful post on MongoDB Atlas + Meteor:

Configuring your write concern can be done by adding this to your MONGO_URL string in your settings.json file:


In MongoDB 4.0+ this is set to false, by default so I have added this on the ends of my MONGO_URL config in my settings.json file


Here are some other helpful links: