I recently took over the frontend team’s service stability governance and encountered some very distinctive production issues. Here I’ll document one particularly “interesting” bug hunt.

Our team recently migrated two projects to degg 2.0, and both exhibited serious memory leak issues. Here I’ll use the tracking service I maintain as an example for debugging. After going live, memory growth looked like the chart below—the red box marks the degg 2.0 production runtime window. Within just 36 hours, memory had grown to 50%, while it normally stabilized at 20%-30%, clearly indicating a memory leak.

Testing your Node.js applications with Jest