server-timings

Server Timings

This is a very early release of server-timings module, intended as an Express middleware.

Usage

Firstly you need to load the middleware as early as possible to record the request timing:

const express = require('express');
const app = express();
const timings = require('server-timings');

app.use(timings);
app.use(require('./routes'));

This will automatically add a Server-Timing header shown in milliseconds (note that in stable Chrome shows timings in seconds, this will change):

$ curl https://jsonbin.org/remy/urls -I
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server-Timing: 0=72.45; "Request"

To include additional timings the middleware exposes two methods on the res.locals.timings property:

• start(label) - record the start time
• end(label) - end the record time - if this isn't called, it will be called when the request is finished

Start/end as middleware

As well as being exposed in res.locals.timings you can also call start and end as middleware:

app.use(timings);
app.use(timings.start('routing'));
app.use(require('./routes'));
app.use(timings.end('routing'));

Live example

See jsonbin.org for a working example. As of March 2017, the networking timings can be seen in Canary:

Limitations

• Currently only ES6 support (not tranpiled down to ES5…yet)
• Expects next() so limited to Express
• Currently no tests(!)