Topic
Everything filed under observability, across every section.
Learn to distinguish a blocked Node.js event loop from slow downstream I/O using event-loop delay, event-loop utilization, request timing, and CPU measurements. Includes instrumentation code, a diagnosis matrix, and concrete remediation decisions.
Use Node.js event-loop delay and utilization metrics as an incident decision system. This guide shows what to measure first, how to distinguish synchronous blocking from CPU saturation and downstream I/O pressure, and when code changes are actually justified.
A Node.js process can remain running, pass a health check, and still make every request slow. This practical guide shows how to reproduce that failure, collect event-loop metrics beside latency, and decide whether the event loop is actually the bottleneck.