This is a simple example showing how to make NodeJS utilize your processor threads.
The example makes use of an simple Express instance for HTTP serving.
The express application can be found in ./server/app.js, the NodeJS app useing cluster to run the web server on multiple threads is the index.js script.
Have a look at both scripts, the comments are sure to help.
Here's a blog post containing a stress test experiment with single and multi-threaded NodeJS instances.
NOTE For Heroku Apps you'll want to use a ratio of the threads you are provided with else you run the risk of exceeding the Memory Limit designated to your application. See below a quick example of how you could manage this with Heroku.
In line 8 of index.js you should have
let numCPUs = require('os').cpus().length / (parseInt(process.env.CLUSTER_DIVIDER, 10) || 1);Where CLUSTER_DIVIDER is a config variable that determines the divider to be used. For Heroku most packages (Free and Standard 1X), you get 8 threads on a Intel(R) Xeon(R) CPU E5-2670 v2 @ 2.50GHz, so you'll want to use a divider of 2 (meaning you use only 4 threads) to avoid consuming all 512 MB of RAM. If your plan is up to 1 GB RAM then 8 threads will be fine.
You might want to checkout ./tests/main.spec.js and see how we test the multi-threading.