Everyone speaks about microservices. Today we want to create our first node.js microservice based on an article in the current phpmagazin.
On top we want to add this microservice to a servicecluster, which can scale perfect to your hardware and doubles your number of request per second to 10000 hits / sec
Prerequisits
We need some things installed on the local machine.- node.js and npm installed
If you have installed the node and npm we can proceed
Create a npm project
-npm initThis will open a promt to fill your projectdata
Install needed node libraries
We need express.js as a webserver framework, SQLite.js as the database-layer and body-parser to process responses-npm install --save express body-parser cluster
Create index file
Our index.js references the libraries, implements the router and starts the app on port 8085Here is the index.js
const express = require('express');
const bodyParser = require('body-parser');
const app = express();
app.use(bodyParser.urlencoded({extened:false}));
require('./lib/router')(app);
app.listen(8085);
Create your routings
Our service implements 6 routes:| URL | HTTP Method | Description |
| /timetrack/ | GET | READ all entries |
| /timetrack/user/:id | GET | READ a user entry |
| /timetrack/id/:id | GET | READ an entry |
| /timetrack/ | POST | add an entry |
| /timetrack/:id | PUT | update an entry |
| /timetrack/:id | DELETE | delete an entry |
Lets create this routes in the folder "lib" (create this folder) by adding a file "routes.js"
This simple router just takes the requests and returns a static string, so that we can see the router working
lib/router.js
module.exports = function (app)
{
app.get('/timetrack/id/:id', (req, res)=>
{
res.send('Returning a specific item');
});
app.get('/timetrack', (req, res)=>
{
res.send('Returning all items');
});
app.post('/timetrack', (req, res)=>
{
res.send('add an item');
});
app.put('/timetrack/:id', (req, res)=>
{
res.send('updating an item');
});
app.delete('/timetrack/:id', (req, res)=>
{
res.send('delete a specific item');
});
};
Create your cluster
Cluster.js gives us the possibility to create 1 nodeprocess per cpu. So you can scale your node app with factor 8 on a octacore i7This will double the number of request per second.
cluster.js
var cluster = require('cluster');
var numCPUs = require('os').cpus().length;
if (cluster.isMaster) {
console.log('#######################################');
console.log('found:' + numCPUs + ' cpus on this server:');
console.log('#######################################');
for (var i = 0; i < numCPUs; i++) {
console.log('starting cluster instance on cpu:' + i);
cluster.fork();
}
cluster.on('exit', function(worker, code, signal) {
console.log('worker ' + worker.process.pid + ' died');
});
} else {
//change this line to Your Node.js app entry point.
require("./index.js");
}
Test your service
node index.js
Open a second terminal and run
ab -n 10000 -c 1000 http://localhost:8085
Now we want to scale our service:
Stop your app and restart it with
node cluster.jsRestest the service and compare the results
ab -n 10000 -c 1000 http://localhost:8085
As you can see, in the first test we got 5448 Request per second. On the second test with cluster.js we have 10756 Requste per second. This is more then double the perfomance.
Realy awsome
