Why Round-Robin Won't Save You: Load Balancing Challenges in Data Streaming Services With Heterogeneous Traffic

If you've ever run a data streaming service that handles more than one type of workload, you've probably hit a wall that no amount of round-robin tuning can fix. This is a common failure mode in production streaming environments. This post is about the specific ways traditional load-balancing strategies break down when your traffic isn't uniform.

I'll focus on CPU utilization as the primary example throughout, since it's the most common bottleneck in compute-heavy streaming workloads, but the same principles apply to memory, network bandwidth, and other system resources.