Operating a popular website is a challenging task. Users not only expect services to always be available, but also good performance in the form of fast response times. To achieve high availability and avoid performance problems which can be linked to user satisfaction and financial losses, the ability to balance web server traffic between servers is an important aspect.
This study is aimed to evaluate performance aspects of popular open-source load balancing software working at the HTTP layer. The study includes the well-known load balancers HAProxy and NGINX but also Traefik and Envoy which have become popular more recently by offering native integration with container orchestrators. To find performance differences, an experiment was designed with two load scenarios using Apache JMeter to measure the throughput of requests and response times with a varying number of simulated users.
The experiment was able to consistently show performance differences between the software in both scenarios. It was found that HAProxy overall had the best performance in both scenarios and could handle test cases with 1000 users where the other load balancers began generating a large proportion of failed connections significantly better. NGINX was the slowest when considering all test cases from both scenarios. Averaging results from both load scenarios excluding tests at the highest, 1000 users, concurrency level, Traefik performed 24% better, Envoy 27% better and HAProxy 36% better compared to NGINX.