Locating speed bottlenecks in php

how do I figure out what is slowing my script down?

[erikcw]

Hi all,

Can anyone share some tips on how to identify slow code in large php scripts?

I have a "wizard" script - index.php, it includes a seperate php file as the user works through each section of the script. Problem is that sometimes it seems to slow to a crawl when loading session data from mysql. I checked my server load, and it is normal.

Any ideas on how I can figure out what is causing the slow down?

Thanks!

[sned]

You might be able to use microtime [us3.php.net] as a way to see how long a function or script is taking.

Something like:

$start_time = microtime();
// run script code here
$end_time = microtime();
$total_time = $end_time - $start_time;

There's quite a few code samples on the microtime page that you might find handy.

-sned