Error: connect ECONNREFUSED in production for only one request caused unhandled rejection

MongoDB Atlas
1

I have a site running in production. The backend connects to mongo atlas cloud.

Error: connect ECONNREFUSED 52.202.136.90:27017 caused an unhandled rejection. What does this error mean?

I found reports of a similar error, but for those reports the error prevented connection to mongo entirely. On the other hand, my backend was already running in production and had been making connections to my mongo atlas cloud database before I got this error. I have a lot of activity on my site, yet this only happened with one request.

Heroku uses a range of AWS IP addresses. So I have 0.0.0.0/0 (includes your current IP address) in my IP Access list for Network Access to account for their changing IP’s.

I’m not sure what’s causing this which also means I’m not sure where to look to add some error handling or what this concerns.

Backend logs

Jul 02 15:24:25 myapp app/web.1 2022-07-02T20:24:25.105Z silly: OPTIONS: /api/posts/62c0a45ad56ea20004014196 
Jul 02 15:24:25 myapp app/web.1 2022-07-02T20:24:25.197Z silly: PATCH: /api/posts/62c0a45ad56ea20004014196 
Jul 02 15:24:25 myapp app/web.1 allowedOrigin https://www.mysite.com 
Jul 02 15:24:25 myapp app/web.1 node:internal/process/promises:279 
Jul 02 15:24:25 myapp app/web.1             triggerUncaughtException(err, true /* fromPromise */); 
Jul 02 15:24:25 myapp app/web.1             ^ 
Jul 02 15:24:25 myapp app/web.1 Error: connect ECONNREFUSED 52.202.136.90:27017 
Jul 02 15:24:25 myapp app/web.1     at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1187:16) { 
Jul 02 15:24:25 myapp app/web.1   name: 'MongoNetworkError' 
Jul 02 15:24:25 myapp app/web.1 } 
Jul 02 15:24:25 myapp heroku/web.1 State changed from up to crashed 
Jul 02 15:24:25 myapp heroku/web.1 State changed from crashed to starting 
Jul 02 15:24:25 myapp heroku/router at=error code=H13 desc="Connection closed without response" method=PATCH path="/api/posts/62c0a45ad56ea20004014196" host=api.mysite.com request_id=f2f05673-f516-49d1-b2c4-e07f33b5bc8a fwd="45.49.3.242" dyno=web.1 connect=0ms service=38ms status=503 bytes=0 protocol=https
2

What do you get when trying to go at http://portquiz.net:27017?

4

Outgoing port tester

This server listens on all TCP ports, allowing you to test any outbound TCP port.

You have reached this page on port 27017 (from http host header).

Your network allows you to use this port. (Assuming that your network is not doing advanced traffic filtering.)

Network service: unknown
Your outgoing IP: 7…

But I’m confused why this matters. The error I got wouldn’t concern my local environment.

5

You are totally right. You have to do it from the machine that has the connection issue. The machine that gets ECONNREFUSED.

7

That’s heroku’s servers