Facebook was kind enough to open source the XHProf extension last year, but it flew under my radar until I saw a presentation including it earlier this year when they showed off HipHop. XHProf provides profiling information about your application, while being lightweight enough to run on a production server (against a percentage of requests). Once we got it installed we ran into a few limitations with the existing GUI. With the help of Graham Slater (one of our front end designers) I hacked on the Facebook code to come up with our own flavor. Let me stress the word “hack." I was given some really tough deadlines for this project so functionality was literally hacked into the existing codebase.

Key Features:

Nice interface

MySQL backend for data storage

Stores key values such as Peak Memory Usage, Wall Time, and CPU Ticks in the database directly for easy lookup.

Stores Get, Post, and Cookie data for easy comparison (so you can determine why a run hit that execution path)

Display includes easy lookup for worst runs, most recent, etc.

Support for profiling a percentage of requests, or on demand

Support for not including a link to profile requests on certain files (like xml documents, images, etc).

Uses Google Data Visualization API to graph runs over time

Concept of “Similar” urls, to handle ?story=23 and ?story=24 having different URLs, but similar to identical code execution paths

Screenshots:

Download:

Please download the source code from GitHub

Warnings:

Seriously, we hacked this up! Please let me know if you encounter any bugs, there's probably a bunch.