Mongodb: Cannot read property 'points' of null at RateLimiterMongo._getRateLimiterRes

There seems to be an issue when using a clustered connection from MongoDB Atlas. I tried the same setup both on a local server and a mongodb Atlas server, there is always an error on the first consume when testing on the Atlas server.

Setup: “MongoDB”: 5.0.6 “Mongoose”: “^6.2.2”, “NodeJS” : 14.18.1

const limiterSlowBruteByIPOps = {
  keyPrefix: '',
  storeClient: dbConnection,
  tableName: 'login_fail_ip_per_day',
  points: maxConsecutiveFailsByAccountAndIP,
  duration: 60 * 60 * 24 * 90, // Store number for 90 days since first fail
  blockDuration: 60 * 60 * 24 * 365 * 20, // Block for infinity after consecutive
};

When using local server: Localhost

in RatelimiterMongo.js line 14

 _getRateLimiterRes(rlKey, changedPoints, result) {
    const res = new RateLimiterRes();

    let doc;
    if (typeof result.value === 'undefined') {
      doc = result;
    } else {
      doc = result.value;
    }

    **res.isFirstInDuration = doc.points === changedPoints;**
    res.consumedPoints = doc.points;
   ....
}

the result value coming in from the this._collection.findOneAndUpdate on the first consume looks like this

First consume call => no error on localhost
{
  lastErrorObject: {
    n: 1,
    updatedExisting: false,
    upserted: new ObjectId("621feaf6404e93c2a20983d7")
  },
  value: {
    _id: new ObjectId("621feaf6404e93c2a20983d7"),
    key: '::1',
    expire: 2022-05-31T22:08:54.769Z,
    points: 1
  },
  ok: 1
}

Second consume localhost call => no error on localhost

{
  lastErrorObject: {
    n: 1,
    updatedExisting: true
},
  value: {
    _id: new ObjectId("621fedca404e93c2a20985c4"),
    key: '::1',
    expire: 2022-05-31T22:20:58.609Z,
    points: 2
  },
  ok: 1
}

however, when testing with the mongoDB Cluster I get a different result format generating the error.

MongoDb Cluster

First consume to Atlas cluster always throw error

{
  lastErrorObject: {
    n: 1,
    updatedExisting: false,
    upserted: new ObjectId("621fec0568d6587a94266266")
  },
  value: null, // **value here is null and throws error on this line "res.isFirstInDuration = doc.points === changedPoints**;"
  ok: 1,
  '$clusterTime': {
    clusterTime: new Timestamp({ t: 1646259205, i: 3 }),
    signature: {
      hash: new Binary(Buffer.from("9406443ec068e13b88f3a0f867044c3d4d18afa0", "hex"), 0),
      keyId: new Long("7020773886748786690")
    }
  },
  operationTime: new Timestamp({ t: 1646259205, i: 3 })
}

Second consume to Atlas => no error

{
  lastErrorObject: {
		n: 1,
		updatedExisting: true
	},
  value: {
    _id: new ObjectId("621fec0568d6587a94266264"),
    key: '::1',
    expire: 2022-05-31T22:13:26.591Z,
    points: 1
  },
  ok: 1,
  '$clusterTime': {
    clusterTime: new Timestamp({ t: 1646259511, i: 4 }),
    signature: {
      hash: new Binary(Buffer.from("aebd4a7b566496affeb8c2bbb7622add8f84043d", "hex"), 0),
      keyId: new Long("7020773886748786690")
    }
  },
  operationTime: new Timestamp({ t: 1646259511, i: 4 })
}

Am I doing this wrong or is there a bug?

[ywilkof]

This is happening to me when using rate-limiter-flexible (2.3.6), mongoose (6.2.7) and mongo-memory-server (8.4.1). I get the exact same error message, and my solution is the same – downgrading to mongoose 5.X solves the issue. This leads to me to assume this is not an atlas issue specifically.

[animir]

@donaldkg Hey. It is not about this package, it is about how you structure your code. You can use old-school then / catch promise handlers. Or you can make a separate function getMongoConnection and use it in your project. Or you can create separate script, place all limiters there and then export getMongoLimiter function. Yes you’ll need to deal with promises anyway, but that’s how mongoose works now.