Apache 2.2 vs Nginx 0.7: Surviving the C10k Problem on Your VPS

The Process-Based Dinosaur vs. The Event-Driven Racer

If you are running a high-traffic site on a standard 512MB VPS, you have likely seen it: the dreaded load average spike. You check top, and there it is—dozens of httpd processes, each consuming 20-30MB of RAM, choking your swap partition. Your site isn't just slow; it's timing out.

It is 2009. We shouldn't be struggling to serve 10,000 concurrent connections (the C10k problem). Yet, the default LAMP stack configuration on most Red Hat and Debian distributions sets you up for failure.

At CoolVDS, we see this daily. Clients upgrade their RAM when they should be upgrading their architecture. Today, we break down the battle between the entrenched king, Apache 2.2, and the Russian challenger rewriting the rules, Nginx.

Apache 2.2: The Heavy Lifter

Apache is the standard. It powers over 50% of the internet. Its strength lies in its modularity and the ubiquity of .htaccess files. If you are a hosting provider or running a shared environment, Apache is non-negotiable because it allows users to override settings per directory.

However, Apache's default Multi-Processing Module (MPM), Prefork, is a memory hog. It spawns a separate thread for every single connection. If you have 200 users downloading images, Apache keeps 200 threads open, sitting idle, wasting RAM. On a strict VPS allocation, this leads to the OOM (Out of Memory) killer terminating your database.

Nginx: The Asynchronous Challenger

Nginx (Engine-X) takes a different approach. It uses an event-driven, asynchronous architecture. Instead of spawning a process for every connection, it handles thousands of connections in a single worker process. It doesn't block.

In our benchmarks here in Oslo, replacing Apache with Nginx for static content serving dropped memory usage from 450MB to a mere 40MB under similar load.

The Strategy: The Nginx Reverse Proxy (The Hybrid)

You don't have to choose. The smartest architecture we see deployed on CoolVDS slices is the Hybrid Setup. You place Nginx in front on port 80 to handle the heavy lifting (images, CSS, JS), and proxy PHP requests to Apache running on port 8080.

Here is a battle-tested configuration snippet for nginx.conf (v0.7.6x):

server {
    listen 80;
    server_name example.no;

    # Serve static files directly (NVMe-like speeds on RAM)
    location ~* \.(jpg|jpeg|gif|png|css|js|ico)$ {
        root /var/www/html;
        expires 30d;
    }

    # Pass dynamic content to Apache
    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

Pro Tip: If you are running PHP 5.2, consider ditching Apache entirely and using Nginx + PHP-FastCGI (spawn-fcgi). It is trickier to configure than `mod_php`, but the performance gains on a 256MB VPS are massive.

Latency and Geography: The Norwegian Context

Software optimization means nothing if your network latency is high. If your target audience is in Norway, hosting in Germany or the US adds 30-100ms of latency before the server even accepts the handshake.

CoolVDS infrastructure is physically located to optimize peering with NIX (Norwegian Internet Exchange). When you combine Nginx's sub-millisecond request handling with our low-latency routing, your Time To First Byte (TTFB) drops significantly. This is critical not just for user experience, but for keeping your bounce rates low.

Data Integrity and Hardware

While we optimize software, hardware realities persist. We use enterprise-grade SAS RAID-10 arrays. Why? Because when Nginx flushes logs or Apache writes sessions, you need high write speeds. Cheap VPS providers oversell I/O, causing "iowait" to spike even if your CPU is idle.

Furthermore, adhering to the Personopplysningsloven (Personal Data Act) means you need to know exactly where your physical data resides. With CoolVDS, your data stays within the jurisdiction, safe and compliant.

Conclusion

If you are serving purely dynamic content with complex .htaccess rules, stick to Apache, but tune your MaxClients setting carefully to fit your RAM. If you need raw speed and concurrency, put Nginx in front.

Don't let a default config file kill your server. Spin up a fresh CentOS 5 instance on CoolVDS today and test the Nginx proxy setup yourself. We guarantee your load averages will thank you.