leak.js

var zlib = require('zlib');


var iteration = 0;
var maxRss = 0;

(function leak() {

    if (iteration % 1000 === 0) {
        var usage = process.memoryUsage();
        maxRss = Math.max(maxRss, usage.rss);
        console.log('MEMORY USAGE current: ' + JSON.stringify(usage) + '; max rss: ' + maxRss + '; iteration: ' + iteration);
    }
    iteration++;

    zlib.gzip('this is some test data', function() {
        process.nextTick(leak);
    });
    
})();

This gist demonstrates a bad behavior of zlib, where RSS will grow to very high levels rapidly. in my tests, within a handful of seconds RSS is well over 500MB. This repros on node 0.8.18. It is fixed in 0.9.8.

see nodejs/node-v0.x-archive#4172