Mongodb connection disconnected after 2-3 hrs

Mongodb connection diconnected after 2-3 hrs.

My backend application is running on AWS Lamba on the top of API gateway. Its a monoletic application which has 20+ endpoints.

Network access - (includes your current IP address)

I am trying to connect mongo from there - First 2-3 hrs it is working fine. Then I am getting this below error. -

ab64f03c-c8f9-43fb-8cb0-20197289717f	INFO	MongooseServerSelectionError: Could not connect to any servers in your MongoDB Atlas cluster. One common reason is that you're trying to access the database from an IP that isn't whitelisted. Make sure your current IP address is on your Atlas cluster's IP whitelist:
    at _handleConnectionErrors (/var/task/node_modules/mongoose/lib/connection.js:791:11)
    at NativeConnection.openUri (/var/task/node_modules/mongoose/lib/connection.js:766:11)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async /var/task/db.js:12:7 {
  reason: TopologyDescription {
    type: 'ReplicaSetNoPrimary',
    servers: Map(3) {
      '' => [ServerDescription],
      '' => [ServerDescription],
      '' => [ServerDescription]
    stale: false,
    compatible: true,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    setName: 'atlas-xsqkyc-shard-0',
    maxElectionId: null,
    maxSetVersion: null,
    commonWireVersion: 0,
    logicalSessionTimeoutMinutes: null
  code: undefined

When I ran the same code from Ec2, it is working fine.

How I am connecting mongo -

const mongoose = require('mongoose');
const config = require('config');
const chalk = require('chalk');

// Mongodb ServerUrl

const connectUrl = 'const connectUrl = mongodb+srv://abbakid:<password>';

(async () => {
    try {
      await mongoose.connect(connectUrl, {
        useNewUrlParser: true,
        useUnifiedTopology: true
      console.log(chalk.yellow('MongoDB connected...', connectUrl));
    } catch (err) {
        console.log('Error in DB connection: ' + err));

module.exports = mongoose;

Any idea what I am doing wrong.

Hi @Atique_Ahmed - Welcome to the community.

Firstly, thanks for providing all those details including the error and connection portion of the code.

I’d like to gather a few more details regarding this scenario:

  1. You’ve tested the connection from the EC2 instance and Lambda to the same Atlas cluster but only the EC2 instance has a stable connection - Is this correct?
  2. What is the instance tier or type for your Atlas cluster.
  3. Besides the code being run on EC2 vs Lambda, is the application portion (versions, etc) all the same between the 2 environments?