Agent Wranglers

Performance Optional

Report how long the server took

Report how long the server took in a Server-Timing header, without internal names.

By Erik Bergstedt, Agent Wranglers. Updated .

How to do it

Measure the time from request start to writing the headers. Send it as Server-Timing: app;dur=<ms>, with generic metric names.

Example

HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
Server-Timing: app;dur=4.2

How to check

curl -sI URL shows Server-Timing with a dur value, and no metric name reveals a database, host or library.

For agents: if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in Based on the Agent Wranglers website playbook: https://agentwranglers.se/playbook/website/performance/server-timing.