Nginx Server not responding - nginx

Nginx server is not responding periodically like every 30 minutes.
I have to reload it by nginx -s reload.
How to resolve the problem?
I can able to ping host. But unable to establish http request.

Problem solved after updating to latest version of nginx 1.2.3 to nginx/1.11.3

Related

Consul-template nginx upstream not found

I have nginx in which consul-template prescribes upstream for golang services.
When deploying, the service is started and registered with consul, after which consul-template writes it upstream. After that, nginx -t is checked and an error is generated that upstream is not found.
The problem is floating, because sometimes the deployment is successful
Can you help me understand what could be wrong?

Node js Application running on EC2 but not accessible in browser using Nginx

I'm a newbie to Nginx. I cannot access my Node.js application that I deploy on AWS EC2 using Nginx reverse proxy. If I do curl http://localhost:3000 I can see the application is running successfully on the server(I'm using pm2 for running node server). But when I try to access it in my browser or postman using public DNS I get the error This site can't be reached and the request gets timeout. Here's my Nginx configuration (I have followed a number of tutorials for this)
The configuration file is named nginx.conf and is in /etc/nginx/sites-enabled directory. If I do sudo nginx -t it says syntax is ok and the test is successful. Also I can see the Nginx is running using command sudo systemctl status nginx What could be the possible reason for this behaviour?
I figured it out the problem wasn't with the Nginx configuration actually I needed to allow public access for port 80 on my ec2 instance which is blocked by default. I allowed port 80 and everything is working fine. This blog helped me. Visit it for me details on how to enable port 80 for your ec2 instance.

What is NGINX [notice] signal process started error message

With regards to nginx error log, what does 2020/10/23 06:51:45 [notice] 361#361: signal process started mean?
Some more context:
I have some raspberry pi's communicating with my Django application on a digital ocean Ubuntu droplet running nginx as the web server. These raspberry pi's stopped communicating with my server and they are physically very far from me. I can see their last communication with my server was at 2020/10/23 06:51:41 then they stopped (seconds before nginx error message was logged).
A user that has access to the pi's said they did not lose power, internet is working, so they did a reboot, still nothing.
I have tried:
sudo systemctl restart nginx followed by sudo systemctl restart gunicorn
This did not resolve the issue. I can't seem to find the documentation on this error
Have you verified the security group of your instance from digital ocean ? I think your port is not opened for http and HTTPS. Cross check for port 80 and 443. Is it opened or closed.

What's the difference between starting nginx with command "nginx", "service start nginx" and "systemctl nginx start"?

I have noticed that when ever I start nginx with ubuntu command "nginx" and I do systemctl status nginx. It shows that systemctl is disabled. More over if I first start nginx with command systemctl start nginx and i try to start nginx with command nginx, it check the availbility of the ports and then says nginx: [emerg] still could not bind(). So i thought there must be a differene and their purpose. When I strt nginx with command nginx the only way to stop nginx is by the means of force using killlall nginx or kill -9 (process id) or by clearing the port. So I am pretty sure there is some difference in them.
The difference between the examples you have provied is how the processes are being started.
Running the command nginx will start the application and wait for your user action to stop it.
The systemctl or service commands are nearly the same thing and running service nginx start or systemctl start nginx will start a service in the background running the Nginx daemon.
You can also use this to do a service nginx restart or systemctl restart nginx to restart the service, or even a service nginx reload / systemctl reload nginx to reload the configuration without completely stopping the Nginx server.
The reason why you can't do both nginx and systemctl start nginx is due to the nginx configuration already listening port 80, and you can't listen on the same port on a single IP address at the same time.
You can also force the nginx service to start on boot by running systemctl enable nginx which will be why your systemctl status nginx returns 'disabled'.
Hope this makes sense.
service command is just a simple script which basically abstract choosing the underlying init system (upstart, systemmd , /etc/init.d or systemctl).
since it being a very concise script, it only supports a very limited set of operations (start | stop | reload .. ).
However, if you actually want to perform the additional operation you need to make use of the actual init system in this case systemctl
An apt example would be starting the service on boot time using systemctl sudo systemctl enable the-name-of-service which is not possible using service

Varnish Cache - Connection Refused

I have Nginx running on 8080, while Varnish runs on port 80. I can do
wget localhost:8080
in shell and get a response, but if I run
wget localhost
I get connection refused. For reference, I'm trying to access it externally but get the same problem. Hopefully I can solve access from localhost first!
Thanks in advance!
netstat -tulnp shows you every port and service running
iptables -L shows you if port open or blocked
cheers

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