MongoDBConnectionTimeout

checkTimeout.js

const NodeCache = require('node-cache');
const axios = require('axios');
const { exec } = require('child_process');

const cache = new NodeCache();
const cacheId = 'MONGODB_TIMEDOUT_MONITOR';
const discordWebhook = 'WEBOOK_URL';
const regExp = new RegExp('Server selection timed out after (.*) ms', 'gi');

const activity = {
  checkUnderRestarting: () => {
    const restarting = cache.get(cacheId);
    return restarting;
  },
  markAsRestarting: () => {
    cache.set(cacheId, true);
  },
  notify2Discord: ({ message, title, description }) => {
    // notify to discord.
  },
  restartServer: () => {
    return exec('pm2 restart server');
  },
};


module.exports = async (error) => {
  if (error.extensions.code === 'INTERNAL_SERVER_ERROR') {
    const errors = error.extensions.exception.errors;
    const targetErrors = errors.filter((err) => {
      const matched = err.message.match(regExp);
      return !!matched;
    });
    
    if (targetErrors.length > 0) {
      if (activity.checkUnderRestarting()) return true;
      activity.markAsRestarting();
      // restart pm2 
      await activity.notify2Discord({
        message: 'Critical error occured!',
        title: error.extensions.code,
        description: targetErrors[0].message,
      });
      activity.restartServer();
    }
  }
  return true;
}

mongodbConnectionTimeout.js

const { ApolloServer } = require('apollo-server-express');
const path = require('path');

const config = require(path.resolve('config'));
const logger = require(path.resolve('config/logger'));
const createSchema = require('./schema');
const checkMongoTimedout = require('./checkTimeout.js');

module.exports = ({ repository }) => new ApolloServer({
  schema: createSchema(),
  formatError: (error) => {
    checkMongoTimedout(error);
    // some additional operation for errors.
    return error;
  },
  context: async (request) => {
    // describe about your context.
  },
  subscriptions: {
    keepAlive: 10000,
    onConnect: async (connectionParams, webSocket, context) => {
      // logic on socket connection.
    },
    onDisconnect: async (webSocket, context) => {
      // logic on socket disconnection
    },
  },
  introspection: true,
  engine: {
    apiKey: config.env === 'production' ? config.apolloEngineApiKey : null,
    useUnifiedTopology: true,
  },
  dataSources: () => ({ something }),
});