blog-post-node-js-handle-connections-mongoose-initial-connection-retry

mongoose-exponential-backoff-reconnect.js

let numberOfMongooseRetries = 1;
const THIRTY_SECONDS = 30000;
const MAX_DELAY_TO_RECONNECT = THIRTY_SECONDS;
async function connectToMongoose() {
  console.log(`attempt ${numberOfMongooseRetries} to connect to mongo`);
  try {
    await mongoose.connect(env.MONGO_DB_CONNECTION_STRING,  { useNewUrlParser: true })
  }
  catch (err) {
    // Note: this is where you would send errors to your error tracker
    console.error('failed to intially connect to mongo', err);
    const timeUntilRetrying = Math.min(MAX_DELAY_TO_RECONNECT, (Math.pow(2, numberOfMongooseRetries) * 1000));
    console.log(`will try reconnecting in ${timeUntilRetrying / 1000} seconds`);

    setTimeout(() => {
      numberOfMongooseRetries++;
      connectToMongoose();
    }, timeUntilRetrying);
  }
}
connectToMongoose();