server.js

const express = require('express');
const app = express();
const port = 3000;

const bodyParser = require('body-parser').json({ limit: '40mb' });

function responseTime(req, res, next) {
    const start = process.hrtime();

    res.on('finish', () => {
        const elapsedHrTime = process.hrtime(start);
        const elapsedTimeInMs = elapsedHrTime[0] * 1000 + elapsedHrTime[1] / 1e6;
        console.log('%s : %fms', req.path, elapsedTimeInMs);
    });

    next();
}

function customJSONParser(req, res, next) {
    let data = '';
    req.on('data', function (chunk) {
        data += chunk;
    });
    req.on('end', function () {
        req.body = JSON.parse(data);
        next();
    });
}

app.use(responseTime);

app.post('/bodyparser', bodyParser, (req, res) => res.send('ok'));
app.post('/customparser', customJSONParser, (req, res) => res.send('ok'));
app.post('/noparser', (req, res) => res.send('ok'));

app.listen(port, () => {
    console.log(`Example app listening at http://localhost:${port}`);
});

/*

for i in {1..50}; do
   curl -X POST -H "Content-Type: application/json" -d @./prefetched_data.json http://localhost:3000/noparser
done

*/

stdout

Example app listening at http://localhost:3000
/customparser : 199.639283ms
/customparser : 158.116242ms
/customparser : 139.22439ms
/customparser : 180.091602ms
/customparser : 217.681586ms
/customparser : 172.449014ms
/customparser : 161.213945ms
/customparser : 155.15234ms
/customparser : 182.308572ms
/customparser : 162.155039ms
/customparser : 137.048819ms
/customparser : 164.45414ms
/customparser : 221.564046ms
/customparser : 145.110558ms
/customparser : 162.532367ms
/customparser : 153.213564ms
/customparser : 183.441766ms
/customparser : 165.740644ms
/customparser : 181.128721ms
/customparser : 161.238084ms
/customparser : 164.630121ms
/customparser : 154.260714ms
/customparser : 191.395748ms
/customparser : 136.361023ms
/customparser : 184.794958ms
/customparser : 196.500766ms
/customparser : 155.958258ms
/customparser : 186.504525ms
/customparser : 164.862547ms
/customparser : 157.099748ms
/customparser : 156.32764ms
/customparser : 187.740833ms
/customparser : 173.564101ms
/customparser : 161.290756ms
/customparser : 168.073194ms
/customparser : 158.132257ms
/customparser : 182.405225ms
/customparser : 157.296821ms
/customparser : 157.951096ms
/customparser : 149.944262ms
/customparser : 195.245427ms
/customparser : 133.958814ms
/customparser : 158.922453ms
/customparser : 168.183048ms
/customparser : 216.565111ms
/customparser : 136.532334ms
/customparser : 156.823832ms
/customparser : 208.872034ms
/customparser : 141.004031ms
/customparser : 170.383808ms

Example app listening at http://localhost:3000
/bodyparser : 241.395844ms
/bodyparser : 167.709473ms
/bodyparser : 166.180132ms
/bodyparser : 162.604896ms
/bodyparser : 198.604314ms
/bodyparser : 139.741458ms
/bodyparser : 158.615573ms
/bodyparser : 213.460202ms
/bodyparser : 155.213706ms
/bodyparser : 161.936912ms
/bodyparser : 149.113155ms
/bodyparser : 250.842438ms
/bodyparser : 142.158716ms
/bodyparser : 171.789269ms
/bodyparser : 182.556322ms
/bodyparser : 183.954664ms
/bodyparser : 173.140769ms
/bodyparser : 135.221308ms
/bodyparser : 155.579977ms
/bodyparser : 172.334365ms
/bodyparser : 162.335591ms
/bodyparser : 182.613277ms
/bodyparser : 155.638365ms
/bodyparser : 161.042655ms
/bodyparser : 150.666316ms
/bodyparser : 184.047986ms
/bodyparser : 133.133297ms
/bodyparser : 167.863416ms
/bodyparser : 200.235841ms
/bodyparser : 145.121059ms
/bodyparser : 146.667138ms
/bodyparser : 152.423825ms
/bodyparser : 174.546357ms
/bodyparser : 175.350878ms
/bodyparser : 177.33377ms
/bodyparser : 153.647248ms
/bodyparser : 182.584538ms
/bodyparser : 139.230466ms
/bodyparser : 152.198966ms
/bodyparser : 180.666169ms
/bodyparser : 202.510372ms
/bodyparser : 141.658906ms
/bodyparser : 164.710453ms
/bodyparser : 204.983322ms
/bodyparser : 140.329161ms
/bodyparser : 155.813073ms
/bodyparser : 159.658085ms
/bodyparser : 160.845341ms
/bodyparser : 158.805366ms
/bodyparser : 157.196298ms

Example app listening at http://localhost:3000
/noparser : 4.363301ms
/noparser : 0.68213ms
/noparser : 0.425232ms
/noparser : 0.429087ms
/noparser : 0.440448ms
/noparser : 0.380363ms
/noparser : 0.427211ms
/noparser : 0.447522ms
/noparser : 0.416036ms
/noparser : 0.634677ms
/noparser : 0.32591ms
/noparser : 0.392367ms
/noparser : 0.553544ms
/noparser : 0.474316ms
/noparser : 0.397855ms
/noparser : 0.486129ms
/noparser : 0.339219ms
/noparser : 0.322496ms
/noparser : 0.376357ms
/noparser : 0.37077ms
/noparser : 0.410175ms
/noparser : 0.338254ms
/noparser : 0.324439ms
/noparser : 0.492079ms
/noparser : 0.325762ms
/noparser : 0.336741ms
/noparser : 0.302867ms
/noparser : 0.368071ms
/noparser : 0.426378ms
/noparser : 0.445174ms
/noparser : 0.370928ms
/noparser : 0.344936ms
/noparser : 0.310336ms
/noparser : 0.369327ms
/noparser : 0.363802ms
/noparser : 0.332323ms
/noparser : 0.322526ms
/noparser : 0.323123ms
/noparser : 0.468534ms
/noparser : 0.353477ms
/noparser : 0.324817ms
/noparser : 0.30905ms
/noparser : 0.323495ms
/noparser : 0.316115ms
/noparser : 0.311731ms
/noparser : 0.430025ms
/noparser : 0.320643ms
/noparser : 0.323249ms
/noparser : 0.313192ms
/noparser : 0.314354ms