nanomsg req/rep load balancer example

device.js

var nano = require('nanomsg');
const async = require('async')

function createWorker(index) {
    var worker = nano.socket('rep')
    const endpoint = 'inproc://worker' + index;
    worker.bind(endpoint);
    worker.index = index;
    worker.on('data', (buf) => {
        var a = buf.toString();
        var b = parseFloat(a);
        console.log(`at ${index} received: ${b}`);
        worker.send([index, b, (b * 2)].join('='))
    })
    return worker;
}
var workers = []
for (var i = 0; i < 5; i++) {
    workers.push(createWorker(i));
}

const balancer = nano.socket('req', {
    raw: true
});

workers.forEach((w) => {
    balancer.connect('inproc://worker' + w.index);
})

const server = nano.socket('rep', {
    raw: true
});

server.bind('inproc://server')

nano.device(server, balancer)

// Client side  ///////////////
var client = nano.socket('req')
client.connect('inproc://server');
client.on('data', (d) => {
    console.log('client received: ', d.toString());
})

async.forever((next) => {
    const r = Math.random();
    console.log('sending ' + r)
    client.send(r);
    // we must sleep here, otherwise if we use for loop then we can only get the first response
    setTimeout(next, 100);  
})