master.js

var cluster = require('cluster')
var multilevel = require('multilevel')
var levelup = require('levelup')
var db = levelup('./data')

cluster.setupMaster({
  exec: 'worker.js'
})

cluster.fork()
cluster.fork()
cluster.fork()

Object.keys(cluster.workers).forEach(function (id) {
  cluster.workers[id].on('message', function (m, server) {
    if (m === 'stream') {
      server.pipe(multilevel.server(db)).pipe(server)
    }
  })
})

worker.js

var net = require('net')
var cluster = require('cluster')

var server = net.createServer(function (c) {
  process.send('stream', c)
})

server.listen(3000)