Meteor 1.8 app can't connect to MongoDB Atlas

After upgrading Meteor to 1.8 I’m getting error “MongoError: setName from ismaster does not match provided connection setName” in MongoDB Atlas hosting environment (which is at version 3.6.8).

Is it possible to use Meteor 1.8 with downgraded MongoDB 3.6? Or would I have to downgrade Meteor back to 1.7?

I removed mongo Meteor package which had been upgraded from 1.5.1 to 1.6.0 and ran meteor add mongo@1.5.1, and deleted local directory. But db.version() in Mongo shell still returns 4.0.2.

Here’s the full error output in the hosted app log:

MongoError: setName from ismaster does not match provided connection setName [9b9s-shard-0] != [9]
    at ReplSetState.update (/app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset_state.js:403:14)
    at /app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:809:45
    at applyAuthenticationContexts (/app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:731:12)
    at Server.<anonymous> (/app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:802:7)
    at Object.onceWrapper (events.js:315:30)
    at emitOne (events.js:116:13)
    at Server.emit (events.js:211:7)
    at /app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/server.js:508:16
    at /app/.meteor/heroku_build/app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:532:18
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)

I haven’t yet tried using Mongo 4.0 on Atlas but I have used Meteor 1.8 to connect to Mongo 3.6 on Atlas with zero issues so far.

I haven’t had problems with Mongo 3.6 on Atlas either.
The problem is that Meteor 1.8 (with Mongo 4.0.2) doesn’t run with Atlas (Mongo 3.6.8).

Meteor (with Mongo 3.6.4) runs fine with Atlas (Mongo 3.6.8).

Meteor 1.8 (with Mongo 4.0.2) runs fine with mLab (Mongo 3.6.6).

So there’s some problem with the combination of Meteor 1.8 and Atlas (Mongo 3.6.8).

Correction to the above – I’m actually still on 3.4 on Atlas. What’s the issue you’re running into with 3.6 on Atlas?

I think Meteor 1.8 expects to be working with a Mongo 4 database, causing some error when it’s given a Mongo 3.6 DB to work with.

I migrated the data to mLab and upgraded the app to Meteor 1.8, and it’s OK for now. There’s something definitely wrong with Meteor 1.8 and MongoDB Atlas.