Nginx stops serving passenger app (503)

elasticsearchnginxphusion-passengerserver-crashes

I'm deploying a rails app through passenger and nginx (utilizing an elastic-search server which is running on the same machine) on a Ubuntu system. This works perfectly for about twelve hours. Then, the servers only response is a 503 message. Restarting nginx fixes the problem.

I already looked plenty at the logs of rails/nginx/elasticsearch, but couldn't find any clues on this "crash". Only some generic routing errors are visible.

Is there any other place I could check? How can I effectively debug this behaviour?

Best Answer

503 means service not available, usually maintenance or server can't respond because overloaded.

Assuming all packages related to the deployment are updated, and no external (d)DoS attacks are attempted, does the app/elasticsearch establish many connections outside? Try to have a look to netstat.

Correct way in new versions of nginx

Turn out my first answer to this question was correct at certain time, but it turned into another pitfall - to stay up to date please check Taxing rewrite pitfalls

I have been corrected by many SE users, so the credit goes to them, but more importantly, here is the correct code:

server {
       listen         80;
       server_name    my.domain.com;
       return         301 https://$server_name$request_uri;
}

server {
       listen         443 ssl;
       server_name    my.domain.com;
       # add Strict-Transport-Security to prevent man in the middle attacks
       add_header Strict-Transport-Security "max-age=31536000" always; 

       [....]
}

Best Answer

Related Solutions

nginx HTTPS – How to Serve HTTPS with Same Config as HTTP

NGINX Redirect – How to Rewrite All HTTP Requests to HTTPS While Maintaining Sub-Domain

Correct way in new versions of nginx

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