Shubhra Kar@shubhrakar

April, 2014

Memory Leak Analysis

heapdump for V8 snapshots by @bnoordhuis

npm install heapdumpAdd to app : var heapdump = require(‘heapdump’)

Method 1 : writeSnapshot

Method 2 : SIGUSR2 (Unix only)

Make sure your directory is writable

var heapdump = require('heapdump')...heapdump.writeSnapshot()

kill –USR2 <pid>

process.chdir('/path/to/writeable/dir’)

heapdump for V8 snapshots by @bnoordhuis

Programmatic heap snapshots (timer based)

Programmatic heap snapshots (threshold based)

var heapdump = require('heapdump') ... setInterval(function () {   heapdump.writeSnapshot() }, 6000 * 30) <strong>(1)</strong>

var heapdump = require('heapdump')var nextMBThreshold = 0 <strong>(1)</strong>

setInterval(function () {  var memMB = process.memoryUsage().rss / 1048576 <strong>(2)</strong>  if (memMB &gt; nextMBThreshold) { <strong>(3)</strong>    heapdump.writeSnapshot()    nextMBThreshold += 100  }}, 6000 * 2) <strong>(4)</strong>

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Heapdump analysis in Chrome Dev Tools

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Heapdump analysis in Chrome Dev Tools

StrongOps - Memory Profiling and Leak Detection

A nasty one ! (memory leak)

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Good references

Memory Analysis 101 :https://developers.google.com/chrome-developer-tools/docs/memory-analysis-101

Taming the Unicorn: Easing JavaScript Memory profiling in Chrome DevTools :http://addyosmani.com/blog/taming-the-unicorn-easing-javascript-memory-profiling-in-devtools/

StrongLoop Blog : http://strongloop.com/strongblog/how-to-heap-snapshots/

StrongOps : http://strongloop.com/node-js-performance/strongops/