Can't connect to Lightsail SSH UPSTREAM ERROR 515

Question

Hi, I uploaded an app that took my Lightsail instance into the boostable zone at 40% (normally 0.75%, sustainable limit ~10%) for a moment until I deleted the app. Now I'm getting the UPSTREAM ERROR 515 when I try to SSH into my instance. It has been this way for ~24 hours. The instance is still running and my other apps/websites (DNS etc.) are still running.

I have no attached storage or snapshots. If I take a snapshot now, will this error persist into a new instance based on that snapshot?

Gabriel - AWS · Answer

Hello,  
Thank you for using Lightsail.

The error code 515 tells us the instance is unreachable from our SSH service. It sounds like you've checked that your instance is within burst capacity.
Did you make any changes to the open ports on your instance? Port 22 must be open to allow SSH connections.

There are additional suggestions in this [archived forum post](https://forums.aws.amazon.com/thread.jspa?messageID=965197&#965197)

If the issue is with the SSH key installed on the instance, creating a new instance from snapshot could resolve your connection issue.

Regards,
Gabriel

Piotr Blonkowski · Answer

Hi there!

I have found out the article that might help you with troubleshooting 515 error on Lightsail:

https://aws.amazon.com/premiumsupport/knowledge-center/lightsail-resolve-ssh-console-errors/

There are many reasons that may result in 515 error, so you can try to get more details regarding that:
* Instance boot failures, instance status check failures. or resource over-utilization on the instance.
* An OS-level firewall is blocking SSH port access.
* The default SSH port (22) is changed to a different one.
* The SSH service is down.

Can't connect to Lightsail SSH UPSTREAM ERROR 515

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