Performance impact of async_hooks

• nodejs/diagnostics#124
• nodejs/benchmarking#188

This is a simple demo of the potential performance impact of async_hooks on Promise heavy workloads. This repository contains the popular Bluebird benchmarks and the so-called Wikipedia Promise benchmark with and without async_hooks (running with native promises).

To measure the actual impact there's a version of each benchmark with an empty init hook, i.e. we prepend the following code to the actual code under test:

const async_hooks = require('async_hooks');
const hook = async_hooks.createHook({
    init(asyncId, type, triggerAsyncId) { }
});
hook.enable();

Results

Here the results of running the benchmarks with and without async_hooks enabled:

Benchmark	Node 8.4.0	Node 9.3.0
Bluebird-doxbee (asynchooks)	458 ms	369 ms
Bluebird-doxbee (regular)	301 ms	179 ms
Bluebird-parallel (asynchooks)	1310 ms	1079 ms
Bluebird-parallel (regular)	839 ms	671 ms
Wikipedia (asynchooks)	1656 ms	1790 ms
Wikipedia (regular)	930 ms	863 ms

Bluebird benchmarks

The files here are modified from: https://github.com/petkaantonov/bluebird/tree/master/benchmark

The current version is based on bluebird@c0d4472cecd523c2f9d4805a23d87be3cfe03b41

Wikipedia Benchmark

The files here are modified from: https://github.com/wikimedia/web-stream-util

The current version is based on web-stream-util@fc76740cd6a73dcb044251a233bc3c868d3c9a77