Programming Tutorials

  The most insidious bugs in Go microservices aren't the ones that cause immediate panics; they are the ones that silently degrade performance over weeks. You see a steady sawtooth pattern in your memory usage dashboard. Eventually, the baseline memory consumption exceeds the container limit, the OOM (Out of Memory) killer wakes up, and your pod restarts. This is the classic signature of a  Goroutine Leak . Unlike languages with managed thread pools, Go allows you to spawn lightweight threads cheaply. However, the Go runtime does not automatically garbage collect a goroutine just because it is no longer doing useful work. If a goroutine is blocked and cannot proceed, it will exist forever, holding onto its stack memory (starting at 2KB but often growing) and heap references. This guide provides a rigorous approach to identifying the root cause of these leaks, fixing them using Context cancellation patterns, and preventing regression using automated testing. The Root Cause: Why...

  High CPU utilization and memory bloat in Kubernetes Operators are frequently self-inflicted wounds. The most common culprit isn't inefficient reconciliation logic, but rather   reconciling too often . If your operator reacts to every single event emitted by the API server, your workqueue is likely flooded with noise. Metadata updates, lease renewals, status condition timestamps, and  managedFields  changes trigger the standard  Reconcile  loop by default. For a cluster with hundreds of Custom Resources (CRs), this results in thousands of wasted cycles processing objects that haven't materially changed. This post details how to implement  predicate.Predicate  in the Controller Runtime to filter out irrelevant events and strictly control when your logic executes. The Root Cause: The Noise of the API Server Kubernetes controllers rely on the Informer pattern. They watch for changes to resources. However, the definition of a "change" in Kubernetes i...