Nir Alfasi alfasin

Troubleshooting Production JVMs with `jcmd`

jcmd is a powerful new tool introduced in Java 7. Along with jstack and jps, it should be in your go-to tool for solving production problems on the JVM. (Come to think of it, with this tool you don't really need jps anymore)

Here's an example session with jcmd:

$ ssh wopr.qa.corp.local
$ jcmd -l
34739 sun.tools.jcmd.JCmd -l

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

const Article = require('../../../../app/models/article');

Those suck for maintenance and they're ugly.

Possible solutions

Frontend Development

Attention: the list was moved to

https://github.com/dypsilon/frontend-dev-bookmarks

This page is not maintained anymore, please update your bookmarks.

	#!/usr/bin/env bash

	URL="http://a0.awsstatic.com/pricing/1/ec2/ri-v2/linux-unix-shared.min.js"

	(echo 'function callback(data) { console.log(JSON.stringify(data)); }'; curl -s "$URL") \|\
	node \|\
	jq -r '.config.regions[] \|
	select(.region == "us-east-1") \|
	.instanceTypes[] \|
	[

	// http://stackoverflow.com/questions/11616630/json-stringify-avoid-typeerror-converting-circular-structure-to-json/11616993#11616993
	var o = {};
	o.o = o;

	var cache = [];
	JSON.stringify(o, function(key, value) {
	if (typeof value === 'object' && value !== null) {
	if (cache.indexOf(value) !== -1) {
	// Circular reference found, discard key
	return;