Hello, I’ve just run ./launcher rebuild app with no apparent errors. But when I try to open the site, I get a 502 error. The nginx error log (shared/standalone/log/var-log/nginx/error.log) shows: 2020/08/12 05:47:43 [error] 653#653: *7 connect() failed (111: Connection refused) while connecting to upstream, client: [...], server: _, request: "GET / HTTP/2.0", upstream: "http://127.0.0.1:3000/", host: "[...]" I’ve checked all the topics I found about discourse and nginx 502 errors but couldn’t find or understand anything that makes sense for my case. This might be relevant, running from the container: # netstat -plant Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 644/nginx: master p tcp 0 0 0.0.0.0:5432 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 644/nginx: master p tcp6 0 0 :::6379 :::* LISTEN - tcp6 0 0 :::5432 :::* LISTEN - Is there something that should be running in port 3000? Could you please guide me on where to look for more information to debug this problem? pura vida :slight_smile:

Wooo, looking at the rails logs I found that the unicorn log was huge, complaining about some permission errors. I deleted rm -rf tmp/cache/bootsnap-compile-cache/, and now I see the congratulations screen!!! Thank you friends. I’ll play with this a little more before deciding to recreate it in an SSD server.

It shows 502 initially as the services inside the container are starting up. It should go away within 30 seconds. If it doesn’t it is possible that your server’s CPU is under extreme load and it is causing slowdown.

Thanks @itsbhanusharma. I’ve run ./launcher restart app and monitored the load with top, and it’s well under 10%. I think the CPU should be enough to handle the load: $ cat /proc/cpuinfo | grep 'name' | uniq model name : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz $ cat /proc/cpuinfo | grep process | wc -l 4 Is there a better way to debug the start up of the container? Any other ideas?

Which plugins are installed? Is this server on SSD?

I’ve just cloned the repository and run the setup commands, so I guess it just has the default plugins? Not sure where to check, but I’m sure I’ve added none. The server is not SSD.

Hey @elopio Maybe you can post your ‘yml‘ file without any sensitive info?

Sure, it’s here: Ubuntu Pastebin

[image] elopio: The server is not SSD. Discourse requires SSD, normal spinning drives don’t deliver sufficient IOPS. [image] Which server to choose regarding Discourse requirements? Support You definitely want SSD, the last one seems fine, just check and see if it is a fairly modern CPU.

And is that the cause for the 502 error? Or without an SSD should I see the website working, but very slow?

Using a traditional hard drive versus an SSD drive should not cause a 502 error. That’s not really plausible, as your question indicates @elopio. Here is a little writeup which might be helpful: [image] How to Solve 502 Bad Gateway Issues? - KeyCDN Support Having issues with a 502 Bad Gateway error? This guide gives you practical tips to solve origin not reachable problems. The best thing to do, in my view, is to open up some terminals and run tail -f on your both your Rails and nginx log files, including the error logs and access logs; and then try to access and make sure when you see the 502 error you have your eyes on the tails of the log files. Do you know where those logfiles reside and how to run tail -f commands on them in terminals? Note, you asked earlier: [image] elopio: Is there something that should be running in port 3000? Rails run on port 3000 inside the Docker container and that port is not exposed outside the container. That is why you are not seeing port 3000 outside the container when you run netstat outside the container. HTH

[image] neounix: Using a traditional hard drive versus an SSD drive should not cause a 502 error. Speaking from experience slow IO absolutely can and does cause timeouts and a 502 error. SSD-level IOPS are a firm requirement.

502 error on nginx

Product Support Self-hosting

Stephen (Stephen) August 13, 2020, 1:56am 11

Speaking from experience slow IO absolutely can and does cause timeouts and a 502 error.

SSD-level IOPS are a firm requirement.

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