Go Garbage Collector Mechanics: Pacer, GOGC, and Allocation Latency

Wed, 07 Jan 2026 00:21:12 +0530

In the world of high-throughput backend services, we often obsess over the usual suspects of performance: database indexing, network latency, and algorithmic complexity. But recently, while debugging our core gateway service (backend-gw), I encountered a bottleneck that defied standard logic.

The service was CPU-bound, yet active heap usage was surprisingly low (~200MB). P99 latency was spiking at random intervals, but database queries were returning in milliseconds.

The culprit was not the business logic. It was memory management. I was effectively running a Denial-of-Service attack on my own runtime.

Profiling on Lorbic

Go Garbage Collector Mechanics: Pacer, GOGC, and Allocation Latency