MongoClient initialization fails with secondary read preference and invalid replica set tag set value

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    • Type: Bug
    • Resolution: Works as Designed
    • Priority: Major - P3
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    • Affects Version/s: None
    • Component/s: None
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      3. Which versions of the driver/connector does this apply to?

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      1. What would you like to communicate to the user about this feature? 2. Would you like the user to see examples of the syntax and/or executable code and its output? 3. Which versions of the driver/connector does this apply to?
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      A MongoClient instance fails to initialize successfully when the Read Preference is set to either secondary or nearest, and a Replica Set Tag Set is specified that doesn't currently exists.

      Tested using:

      • Node.js driver v5.7.0
      • mongosh v1.10.2
      • Connection string of mongodb://localhost:27017/?replicaSet=replset&readPreference=secondary&readPreferenceTags=nodeType:ANALYTICS&serverSelectionTimeoutMS=2000

      To validate this behavior, spin up a PSS using mlaunch (MongoDB Server 7.0 used, but this shouldn't be a contributing factor):

      mlaunch init --replicaset --nodes 3

      Now test using the node REPL:

      node
Welcome to Node.js v18.15.0.
Type ".help" for more information.
> var MongoClient = require('mongodb').MongoClient;
undefined
> await MongoClient.connect('mongodb://localhost:27017/?replicaSet=replset&readPreference=secondary&readPreferenceTags=nodeType:ANALYTICS&serverSelectionTimeoutMS=2000')
Uncaught [MongoServerSelectionError: Server selection timed out after 2000 ms] {
  reason: TopologyDescription {
    type: 'ReplicaSetWithPrimary',
    servers: Map(3) {
      'localhost:27017' => [ServerDescription],
      'localhost:27018' => [ServerDescription],
      'localhost:27019' => [ServerDescription]
    },
    stale: false,
    compatible: true,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    setName: 'replset',
    maxElectionId: new ObjectId("7fffffff0000000000000001"),
    maxSetVersion: 1,
    commonWireVersion: 0,
    logicalSessionTimeoutMinutes: 30
  },
  code: undefined,
  [Symbol(errorLabels)]: Set(0) {}
}

      Note this behavior does not reproduce using another driver:

      python
Python 3.10.3 (main, Apr 11 2022, 06:49:33) [Clang 13.1.6 (clang-1316.0.21.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pymongo
>>> from pymongo import MongoClient
>>> client = MongoClient('mongodb://localhost:27017/?replicaSet=replset&readPreference=secondary&readPreferenceTags=nodeType:ANALYTICS&serverSelectionTimeoutMS=2000')
>>> db = client.admin
>>> db.list_collection_names()
['system.version', 'system.keys']
>>> print(pymongo.__version__)
4.3.3

      If the replica set tag set is initialized and the test re-run the failures no longer reproduce.

      mongosh --quiet --eval 'conf = rs.conf(); conf.members[1].tags = { "nodeType": "ANALYTICS" }; rs.reconfig(conf);'
{
  ok: 1,
  '$clusterTime': {
    clusterTime: Timestamp({ t: 1692188462, i: 2 }),
    signature: {
      hash: Binary(Buffer.from("0000000000000000000000000000000000000000", "hex"), 0),
      keyId: Long("0")
    }
  },
  operationTime: Timestamp({ t: 1692188462, i: 2 })
}

node
Welcome to Node.js v18.15.0.
Type ".help" for more information.
> var uri = 'mongodb://localhost:27017/?replicaSet=replset&readPreference=secondary&readPreferenceTags=nodeType:ANALYTICS';
undefined
> var MongoClient = require('mongodb').MongoClient;
undefined
> await MongoClient.connect(uri);
<ref *1> MongoClient {
  _events: [Object: null prototype] {},
  _eventsCount: 0,
  _maxListeners: undefined,
  mongoLogger: MongoLogger {
    componentSeverities: {
      command: 'off',
      topology: 'off',
      serverSelection: 'off',
      connection: 'off',
      default: 'off'
    },
[...]

            Assignee:
            Unassigned
            Reporter:
            Alex Bevilacqua
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              Created:
              Updated:
              Resolved: