How To Optimize Nginx For High Traffic Loads?

Adjusting Worker Processes

Worker processes are Nginx processes that handle incoming requests. Each worker process can handle multiple connections at the same time. The best number of worker processes usually matches the number of CPU cores on your server. This lets Nginx use all available processing power well.

To set the number of worker processes, add this line to your Nginx configuration file:

worker_processes auto;

Using 'auto' tells Nginx to detect and use the best number of worker processes based on your server's CPU cores.

Increasing Worker Connections

Worker connections set the maximum number of connections each worker process can handle. For high traffic, you should increase this value to allow more connections.

To increase worker connections, change the events block in your Nginx configuration:

events {
    worker_connections 19000;
}

This setting allows each worker process to handle up to 19,000 connections at once. The total connections your server can handle is worker_processes * worker_connections.

Setting Worker RLIMIT NOFILE

The worker_rlimit_nofile directive sets the maximum number of open file descriptors for worker processes. Each connection needs at least one file descriptor, so this value should be higher than your worker_connections.

Add this line to your Nginx configuration:

worker_rlimit_nofile 20000;

This setting allows each worker process to open up to 20,000 file descriptors, which works well for high-load scenarios. Make sure this value is higher than your worker_connections to avoid running out of file descriptors during high traffic.

lsof -p $(pgrep nginx) | wc -l

Enabling Gzip Compression

Gzip compression reduces the size of data sent from your server to the client's browser. This speeds up page load times and reduces bandwidth usage. To enable Gzip compression in Nginx, add these lines to your configuration:

gzip on;
gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
gzip_min_length 1000;

This setup compresses common file types and only compresses files larger than 1000 bytes. You can adjust these settings based on your needs.

Implementing Caching Mechanisms

Nginx offers several caching options to improve performance:

• Microcaching: Caches content for a very short time, useful for dynamic content.
• FastCGI caching: Caches responses from FastCGI servers like PHP-FPM.
• Proxy caching: Caches responses from upstream servers.

To set up basic caching, add these lines to your Nginx configuration:

fastcgi_cache_path /tmp/nginx_cache levels=1:2 keys_zone=my_cache:10m max_size=10g inactive=60m use_temp_path=off;

server {
    # ... other server block configurations ...

    location ~ \.php$ {
        fastcgi_cache my_cache;
        fastcgi_cache_valid 200 60m;
        fastcgi_cache_use_stale error timeout invalid_header updating http_500 http_503;
        fastcgi_cache_lock on;
        # ... other PHP handling configurations ...
    }
}

This setup creates a cache zone and caches successful responses for 60 minutes.

Optimizing Keepalive Connections

Keepalive connections allow multiple requests to use the same TCP connection, reducing overhead. To optimize keepalive connections for high traffic, add these lines to your Nginx configuration:

http {
    keepalive_timeout 65;
    keepalive_requests 100;
}

This configuration keeps connections open for 65 seconds and allows up to 100 requests per connection before closing it. You can adjust these values based on your traffic patterns and server resources.

location /nginx_status {
    stub_status on;
    allow 127.0.0.1;
    deny all;
}