Why HAProxy is the Best Opensource Load Balancer for High Traffic Websites


If you’re interested in exploring the performance and scalability benefits of load balancing, then you have to be aware of HAProxy. Find out why HAProxy is the opensource load balancer of choice used by the worlds’ largest websites.

High Availability Proxy (HAProxy) is an open source load balancing and proxy solution for HTTP and TCP servers.

What’s the main benefit of HAProxy you ask?

By distributing connection requests across multiple server nodes, HAProxy can handle enormous volumes of HTTP and HTTPS traffic with very little resource usage (Using Port 80, and Port 443, respectively). 

Twitter, Stack Exchange, Instagram and GitHub use HAProxy to serve millions of users daily

Offhand and speaking on account of EuroVPS, HAProxy’s monitoring dashboard and zero-downtime maintenance activity have made an enormous difference in how we deploy high traffic solutions for our customers.

But these are just a few books amongst many others that HAProxy offers.

Let’s dive in.

Top Benefits of HAProxy Load Balancer

1. Event Driven Architecture for Improved Performance

HAProxy uses single process, event-driven models to handle incoming connections. Unlike pre-forked or threaded approaches, HAProxy’s event-driven architecture minimizes resource utilization–sparing RAM and CPU consumption. 

‘Single-buffering’ skips data copy between reads and writes. This saves multiple CPU cycles and memory bandwidth, allowing HAProxy to simultaneously process hundreds of connection requests without lagging. 

2. Allows Zero-Downtime Maintenance

Rebooting is risky, and can cause outages that can shut down your website and tarnish its reputation.

HAProxy allows you to choose select standby servers. By simply adding IPTable rules to redirect traffic, the standby server can sub in if the primary server requires a reboot. While performing maintenance on the back end, the front end experience remains unaffected. 

3. Supports Traffic Encryption & SSL Termination

HAProxy provides extra security by redirecting HTTP traffic to HTTPS. A user first connects to the HAProxy server via HTTPS. After decrypting the SSL session, the HAProxy server forwards requests to the web server. The web server then encrypts the response before returning it to the user. 

Did you know? HAProxy is the exclusive load balancing technology used in our Managed Cluster hosting product.

HAProxy also decrypts SSL traffic on the load balance level, instead of passing it to the application server. This is called SSL Termination. SSL Termination saves the application server from extra CPU cycles needed to decrypt SSL traffic. 

4. Several Load Balancing Algorithms/Configurations

HAProxy can be uniquely configured in determining how to distribute traffic amongst server nodes. You can configure algorithms globally, or on a server/node basis.

You can also combine Round Robin (RR), Static RR, Least Connection, URI, Source our URL Parameter algorithms depending on your requirements. 

HAProxy can also be configured in TCP mode for general purpose load balancing. 

5. Access to Integrated Server Monitoring Dashboard

HAProxy includes a server monitoring dashboard signifying the health of front-end and back-end server/nodes.

Real-time data for global, server and aggregate stats allow instant detection of disruption, bugs, and errors. 

6. Optimized HTTP Header Analysis

HAProxy parses HTTP headers on the fly.

‘Checkpoints’ optimize parsing by avoiding previously scanned memory areas.

When data is added, HAProxy starts from the checkpoints–not the beginning. 

7. A Cost-Effective Opensource Solution

Given its benefits, HAProxy’s increasing popularity amongst web developers is hardly surprising.

Whether it’s the refreshing autonomy, or the appeal of open source, HAProxy is offering exceptional results– and at zero cost.

Interested in an HAProxy managed solution?

Leverage our experience hosting some of the largest websites and portals in Europe. We combine our expertise, with our decades-long system administration & data centre management experience to deliver bespoke clustered solutions using HAProxy, built to measure. Contact our sales team for a custom quote.