On the NetTuts.com site today there's a new tutorial showing how to use XHProf to profile CodeIgniter-based applications and fidn the spots that are causing the most overhead/issues.

XHProf will provide you with a hierarchical profile of the functions your application calls, allowing you to follow the chain of events that lead up to resource intensive code running. You'll be able to see exactly how much wall time (the actual time elapsed), CPU time and memory your application uses. This tutorial will help you get XHProf installed on your server, and integrated with your CodeIgniter application via hooks so that you can start profiling your application, in a production environment, straight away. Everything you see here was written for Ubuntu 10.04 - the latest LTS release at the time of writing.

They walk you through the installation of the tool (via a wget of the source), show you how to integrate it with CodeIgniter via hooks and include a simple class that is called to execute and report on the findings. Some sample output is included as well as some general tips on interpreting the results.

Kurt Payne has a new post to his blog showing how to use register_tick_function with a callback to help benchmark and profile your application to find its pain spots.

A profiler gives you the ability to trace the performance of your code through every function call and create an overview of your system's performance over a certain time period and helps you make intelligent decisions about where to look for problems. [...] But what if you're in an environment where you can't install [the xdebug or xhprof] extension? Luckily, php has a built-in function called register_tick_function that gives you a way to hook in to every user function that's called. With this, you can write a profiler yourself.

A bit of sample code illustrates his method - it defines a "do_profile" function and assigns it with the register_tick_function call. This function generates a debug backtrace and echos out the function path it took to get to that spot (output is included). He provides code for a bit more useful profiling and points out that it could easily be graphed to help visualize the problems. Also included are a few caveats to watch out for when using this method of profiling.

On DZone.com John Esposito reminds you about another technology Facebook has introduced to the world of PHP (besides HipHop) - XHProf, a PHP profiler.

Facebook did more for PHP: they also created XHProf, a PHP profiler with a (supposedly) easy-to-use HTML interface, designed to pinpoint exactly where your bottlenecks are appearing, so that you can optimize at every stage in the pipeline. [...] If you haven't tried XHProf, you might want to look into it. Installation apparently requires a little nudging, but Nick Lewis just posted a full, practical guide to benchmarking and performance tuning your PHP and MySQL, using XHProf (as well as other techniques) -- a very nice overview of many common bottlenecks and how to open them up.

There's also a link to some Drupal 6 benchmarks that shows how it has helped that project (including both small and large improvements).

On DZone.com's Web Builder Zone today there's a new post from Eric Hogue talking about some of the tools you can use to profile your PHP application and squeeze that much more performance out of it (or maybe just find that pesky, elusive bug).

When developing web applications, we often run into performance issues. People often blame PHP or MySQL for bad performance, but in most case the answer is not that easy. Blindly trying to optimize random parts of our applications can lead to some uneven results. There are many available tools to profile a PHP application. Learning how to use them can help us pinpoint which parts are slow. With this information we can pick the optimizations that will give us the best results.

The helpful tools he mentions include:

• Siege (benchmarking)
• Xdebug
• XHProf
• XHGui

Paul Reinheimer has posted about some updates to a profiler project he's been working on, XHProf, with some new GUI improvements thanks to Highcharts. XHProf is a function-level hierarchical profiler for PHP and has a simple HTML based user interface.

I merged my Highcharts branch into master today, including a bunch of improvements to the GUI for XHProf including: using Highcharts for graphing URLs over time, which allows for multiple axis per graph, adding a pie chart to the individual run page to show where time was spent on page load, ability to merge various calls for display within the pie chart (e.g. mysql_* into mysql), switched to the javascript tablesorter for the single run results, filter to allow you to view results only from a specific server or domain

You can see two screenshots of this new feature in action here and here. If you'd like to give the tool a try, you can grab the latest version from github.

Paul Reinheimer has posted about a new GUI frontend he's developed to sit on top of the XHProf profiling tool and has made available on github.

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.

His deadlines were tight, so he admits the code isn't as robust as it could be, but he does offer a tool that uses MySQL for data storage, keeps stats on things like peak memory usage and wall time and uses the Google Data Visualization API to run graphs of the data over time. You can see a few screenshots of the tool in action in the post including this sample graph and this comparison of two different runs against the same resources.

The project is available for download/contribution on github.

On the IBuildings techPortal site today there's a new article (written up by Lorenz Alberton) about using the XHProf profiling tool as an alternative to the feature used in another popular PHP-related too Xdebug.

In this article, we're going to try another profiler, XHProf, developed at Facebook and open sourced in March 2009 (under the Apache 2.0 license). XHProf is a function-level hierarchical profiler, with a PHP extension (written in C) to collect the raw data, and a few PHP scripts for the reporting/UI layer.

He walks you through the install (either via packages or, if it complains, via the usual PECL build process) and the functions you'd need to profile a chunk of code, an entire page and how to use the UI and reporting output to help define where the real problems are in your code.