Measuring POST performance

The autocannon load tester can also profile POST requests, we simply have to add a few flags.

Let's modify our server.js file so it can handle POST requests at an endpoint we'll call /echo.

We change our server.js file to the following:

const express = require('express')
const bodyParser = require('body-parser')
const app = express()

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: false}));

app.post('/echo', (req, res) => {
  res.send(req.body)
})

app.listen(3000)

We've removed our previous route, added in request body parser middleware, and created an /echo route that mirrors the request body back to the client.

Now we can profile our /echo endpoint, using the -m, -H, and -b flags:

$ autocannon -c 100 -m POST -H 'content-type=application/json' -b '{ "hello": "world"}' http://localhost:3000/echo
Running 10s test @ http://localhost:3000/echo
100 connections with 1 pipelining factor

 Stat         Avg       Stdev    Max
 Latency (ms) 25.77     4.8      156
 Req/Sec      3796.1    268.95   3991
 Bytes/Sec    850.48 kB 58.22 kB 917.5 kB

 420k requests in 10s, 9.35 MB read

POST requests have roughly 65% the performance of GET requests when compared to the results from the main recipe.

Loading the body from a file
If we wish to get our POST body from a file, autocannon supports this via the -i flag.