Change Stream throwing Error "Unauthorised to execute command" with MongoDb Atlas

MongoDB Atlas
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1

Hi,

We have recently migrated our data from Azure Cosmos to MongoDb Atlas. I have a node.js server that watches collections. This code was working perfectly with Azure Cosmos but is throwing the following error when switching out the URL to MongoDB Atlas:

const collection = db.collection(collectionName);
const changeStream = collection.watch([pipeline], { fullDocument: "updateLookup" });
 //listening to changes on the collection with roomId
 changeStream.on('change', (change) => { ... }

Cluster details:
VERSION 6.0.13
CLUSTER TIER M50 (NVMe SSD)
TYPE Replica Set - 3 nodes

connection URL format: “mongodb+srv://user:pass@.mongodb.net/dbName/?&retryWrites=true&w=majority”

I have also granted nearly all permissions on the db (all collections) including find and changeStream from the MongoDB Atlas console.

The full error:

MongoError: not authorized on {dbName} to execute command { aggregate: "system.views", pipeline: [ { $changeStream: { fullDocument: "updateLookup" } }, { $match: { operationType: { $in: [ "insert", "update", "replace" ] } } }, { $project: { _id: 1, fullDocument: 1, ns: 1, documentKey: 1 } } ], cursor: {}, lsid: { id: UUID("") }, $clusterTime: { clusterTime: Timestamp(1707836562, 4), } }, $db: "dbName" }

I have already tried

  • updating and downgrading the node.js driver
  • changing the URL connection string format to other variants suggested on Stack Overflow.

Would really appreciate any kind of help on how to even troubleshoot this!!!

2

Hello. Based on the error, my best guess is that you are trying to open a change stream on a ‘system.views’ collection, and it is not supported as a source for a change stream in MongoDB.

You can open a change stream cursor for a single collection (except system collections, or any collections in the admin , local , and config databases)

If you are looking to track events like creation of the view, you can use database-level change stream with option {showExpandedEvents:true} . It will include events like create/modify describing the creation and modification of collections, including views.

3

Hi Katya,

Thanks for the response! I am actually creating the change stream for a regular collection.

4

hm. Can you share a snippet where you are setting the collectionName?