Investigate a slow Node.js service

Define the observation

Record when the slowdown started, which endpoint is affected and whether the report comes from one client or many. An HTTP status alone does not show which component used the time. Keep request bodies and access tokens out of shared diagnostics.

Compare endpoint and process evidence

An endpoint health check measures one request from the machine running it. An event-loop baseline measures the new local Node process running that script; it does not attach to your production application. To diagnose the application itself, instrumentation must be integrated and reviewed by its owner.

Review captured evidence safely

A HAR export can contain cookies, bearer tokens and personal data. Keep it local, use an authorised export, and share only the necessary summary. Compare slow requests against server logs before blaming DNS, the network or the runtime.

Related tasks in the library

Two designated scripts per desk are included with a free account. Other scripts are preview listings while membership is coming soon.

• Check an HTTPS health endpoint
• Measure a five-second Node event-loop baseline
• Summarise failed and slow requests from a HAR

Reference documentation

• fetch documentation
• node:perf_hooks documentation
• JSON documentation

Written by Tradescore Labs. These are diagnostic starting points, not a guarantee of compatibility or a replacement for your change-control process.