NGINX

NGINX (pronounced “engine-X”) is a very fast webserver for serving out static files, or for caching calls to a slower API.

Why use it?

File Transfer

Problem: You have a remote server from which you are repeatedly downloading the same files, over and over again, and it is obviously not only wasteful but slow.

Solution: Use a NGINX web server to cache some or all of the files locally so that when you browse to localhost, you get an identical copy of the remote file.

Slow API

Problem: A slow API is being called with the same arguments by many different computers, and he exact same value is being recomputed over and over again.

Solution: Use a NGINX web server as a proxy in front of the real API, and let NGINX handle all of the caching.

Installation

The first thing to do is turn off any other web servers that are running. In my case, apache2 happened to be installed and running, so I turned that off.

sudo service apache2 stop

Installing NGINX is straightforward on Ubuntu/Debian:

sudo apt-get install nginx
sudo service nginx start

In the /etc/nginx/nginx.conf file, I put the following in the http block. You may want to edit the path /home/ivar/nginx/cache to be another directory; that is just where I was testing. To make the cache hold data for 1 week, use this inside the http block:

# 10,080 minutes is 1 week
proxy_cache_path /home/ivar/nginx_cache levels=1:2 keys_zone=my_cache:10080m max_size=10g
                 inactive=10080m use_temp_path=off;

server {
   location ~* {
  # access_log off;
  proxy_cache_valid any 10080m;
      proxy_cache my_cache;
      proxy_pass http://potoroo:3003;
   }
}

Finally, force the running server to reload the configuration:

sudo service nginx restart

You can now navigate to http://localhost/ and observe that it hosts a cached copy.

You can watch the nginx access log in real time using:

sudo tail -f /var/log/nginx/access.log

Speed Test

Let’s see how this improves the speed. The first call takes about 12 seconds:

time wget http://localhost/baphy/271/bbl086b-11-1

But the second time you run it, it takes about 52 milliseconds.

time wget http://localhost/baphy/271/bbl086b-11-1

How do I clear the cache?

When you want to clear the cache, simply delete the contents of the nginx_cache directory.

Resources