const { MongoClient } = require("mongodb");

const uri = "mongodb://localhost:14071/?retrywrites=false&directconnection=false"

const client = new MongoClient(uri);

async function run() {
  try {
    await client.connect();

    const database = client.db("sample_mflix");
    const collection = database.collection("movies");
    // create a document to be inserted
    const doc = { name: "Red", town: "kanto" };
    const result = await collection.insertOne(doc);

    console.log(
      `${result.insertedCount} documents were inserted with the _id: ${result.insertedId}`,
    );
  } finally {
    await client.close();
  }
}
run().catch(console.dir);

serene% node test.js
(node:7276) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
MongoError: not master
    at Connection.<anonymous> (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/core/connection/pool.js:451:61)
    at Connection.emit (events.js:315:20)
    at processMessage (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/core/connection/connection.js:452:10)
    at Socket.<anonymous> (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/core/connection/connection.js:621:15)
    at Socket.emit (events.js:315:20)
    at addChunk (_stream_readable.js:295:12)
    at readableAddChunk (_stream_readable.js:271:9)
    at Socket.Readable.push (_stream_readable.js:212:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:186:23) {
  operationTime: Timestamp { _bsontype: 'Timestamp', low_: 1, high_: 1596644733 },
  ok: 0,
  code: 10107,
  codeName: 'NotMaster',
  '$clusterTime': {
    clusterTime: Timestamp { _bsontype: 'Timestamp', low_: 1, high_: 1596644733 },
    signature: { hash: [Binary], keyId: 0 }
  }
}

const { MongoClient } = require("mongodb");

const uri = "mongodb://localhost:14070,localhost:14071/?retrywrites=false&directconnection=false"

const client = new MongoClient(uri);

async function run() {
  try {
    await client.connect();

    const database = client.db("sample_mflix");
    const collection = database.collection("movies");
    // create a document to be inserted
    const doc = { name: "Red", town: "kanto" };
    const result = await collection.insertOne(doc);

    console.log(
      `${result.insertedCount} documents were inserted with the _id: ${result.insertedId}`,
    );
  } finally {
    await client.close();
  }
}
run().catch(console.dir);

serene% node test2.js
(node:7330) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
MongoError: seed list contains no mongos proxies, replicaset connections requires the parameter replicaSet to be supplied in the URI or options object, mongodb://server:port/db?replicaSet=name
    at connectCallback (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/operations/connect.js:358:23)
    at /home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/operations/connect.js:599:14
    at Mongos.<anonymous> (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/topologies/mongos.js:224:11)
    at Object.onceWrapper (events.js:422:26)
    at Mongos.emit (events.js:315:20)
    at Server.<anonymous> (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/core/topologies/mongos.js:416:21)
    at Object.onceWrapper (events.js:422:26)
    at Server.emit (events.js:315:20)
    at Pool.<anonymous> (/home/w/apps/tests/retryable-writes-node/node_modules/mongodb/lib/core/topologies/server.js:384:12)
    at Pool.emit (events.js:315:20)

const client = new MongoClient(uri,{useUnifiedTopology:true});