My Site or Application is Down! It's not serving content. What should I do?

#1

I can’t browse to my website or web application. It’s not serving content or I’m receiving a generic error messages like:

Sorry — this site currently has a problem

There are a number of factors that can lead your application going down. This guide will help you to diagnose some of the most common issues.

The first step is to check that you have sufficient resources on your server:

  • CPU.
  • Memory.
  • Disk space.

Once you have checked this, the next step is to start inspecting key logs to try and determine what is happening.

Is the server currently available? Check with your Cloud Provider

Log in to your Cloud Provider dashboard and check that the server is still online. While you’re there also check the recent status of CPU, memory and Disk Space.

Have any of these metrics been overloaded? If this is the case - this is likely to be the cause of the issue.

You should make sure your server has sufficient resources to run your application.

Can you connect to your server via SSH?

Make an SSH connection to your server. Please remember to open the firewall on the Firewall page in the Cloud 66 dashboard.

Run the top or htop commands. This will show you what processes are running and how much memory and CPU is utilized. If you see excessive load, reboot the server via your Cloud Provider dashboard.

If the server is consistently coming under high load you should investigate upgrading it or scaling your application to use more servers. You can upgrade your server via your Cloud Provider dashboard and you can easily scale up your app by load balancing and firing up additional servers with the Cloud 66 UI.

Try restarting Nginx and check the logs

Run sudo service nginx restart

This will determine whether or not Nginx is having issues starting or serving content. Check the Nginx error logs. You can find these here:

$STACK_PATH/log/nginx_error.log

You should double check your Nginx CustomConfig history in the Cloud 66 Dashboard. See if any recent configuration changes may be causing the problem.

Check your Web Server Logs

There may be an issue with your web server. First check your Stack information page in the Cloud 66 Dashboard to determine what server you’re running.

Passenger Web Server

Check your Passenger logs:

$STACK_PATH/log/<environment>.log

Custom web server (eg. Unicorn)

Check your Unicorn logs:

$STACK_PATH/log/<environment>.log
$STACK_PATH/log/unicorn.stderr.log
$STACK_PATH/log/unicorn.stdout.log

Is HTTPS and SSL correctly installed?

Check to see if your application is redirecting to HTTPS by default, and you don’t have an SSL certificate installed. You can check by visiting the IP address of your server in your browser, or using the following command to see if there is a redirect in place:

curl -I http://www.site.com

The output of this command provides you with lots of useful information, for example response codes, redirects and more. Additionally, an immediate bounce of this command indicates that there is no server listening, whereas a more lengthy response could indicate a firewall issue.

Still can't find the issue? You may need to debug your app on the server

Go to your application path by issuing cd $STACK_PATH From here you can access your framework debugging console.