503 Service unavailable


Recently (over 2wks ago) I received an email from AWS with subject line "Amazon EC2 Maintenance: Instance scheduled for reboot..." about a server maintenance scheduled for yesterday (2023-04-26 08:00:00 UTC). Today is the 27th, and the website we are hosting in the server is no longer reachable. I get this message: "Service Unavailable The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later," and nothing I do will fix the problem.

Please any help I can get to resolve this thorny issue will be greatly appreciated.


asked 10 months ago376 views
2 Answers
Accepted Answer

They would have stopped and restarted your EC2 where your website is hosted.

I suspect either it didnt get powered back on OR its come up with an issue. Check the EC2 where your website is hosted and make sure

  1. The box came back up
  2. Its not powered off
  3. Your IIS, Apache, httpd services are running etc. Check your webserver logs etc.
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answered 10 months ago
  • Thanks very much. I checked the system logs and found an entry that read "Failed to start The PHP FastCGI Process Manager.See 'systemctl status php-fpm.service' for details". I then re-installed php, and rebooted the server. That seems to have done the trick.


You don't say how your service is configured but the simplest option here is that you're running a single server without a load balancer.

If that's the case and you're receiving a 503 error it means that the web server (and therefore the instance itself) is running but there is something wrong in the setup of the web server - it's something you'd need to correct by logging into the instance. The error message you're seeing is being generated by the web server software.

If you're using a load balancer then the same is probably true - you need to check that the server is passing health checks and that the load balancer thinks it is healthy - only then will it pass requests to the web server.

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answered 10 months ago

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