gistfile1.sh

# bash one-liner to run it and watch memory usage
( ./node test.js & PID=$! && trap 'kill $PID' 0; while sleep 1; do ps -o rss= -p $PID; done )

test.js

var sys = require('sys')

function processAll (items, callback) {
    next()
    function next(){
        if(!items.length) callback()
        else processOne(items.pop(), cb)}
    function cb(){
        if(items.length%1000 == 0) sys.puts('Remaining: '+items.length)
        if(items.length%10000 == 0) setTimeout(next, 10000) // wait for gc to happen
        else next()}}

function processOne (item, callback) {
    // Simulate some work
    setTimeout(callback, 2)
}

var items = []
for (i = 0; i < 400000; i++)
    items.push(i)

processAll(items, function() {
    sys.puts("done")
})