best way to measure (and refine) performance with PHP?

Question

A site I am working with is starting to get a little sluggish, and I would like to refine it. I think the problem is with the PHP, but I can\'t be sure. How can I see how long f

Answer 1

I had similar issues and so I created 2 new tables on the database and two new functions. One was audit_sql and the other was audit_code. Because I used an SQL abstraction class it was easy to time every single SQL call (I used php microtime as some others have suggested). So, I called microtime before and after the SQL call and stored the results on the database.

Similarly with pages. I called microtime at the start and end of each page and if necessary at the start and end of functons, divs - whatever I thought might be a culprit.

The general results were:

1. SQL calls to MySQL were almost instantaneous and were nto a problem at all. The only thing I would say is that even I was surprised at the number being executed! The site is generated from the database - even the menus, permissions etc. To produce the home page the SQL calls were measured in the 100s.

2. PHP was not the culprit. This was even more instantaneous that MySQL.

3. The culprit was.... (big build up!) calls to You Tube and Picassa and other sites like that. I host videos and photo albums on the site (well, I don't actually store them - they are stored on YT etc.) and on the home page are thumbnails that are extracted from You Tube and the like via the You Tube PHP API/Zend Framework. Because this is all http based to the other sites, each one was taking 1, 2 or 3 seconds. This was causing those divs containing these to take between 6 and 12 seconds and the home page up to 17 seconds.

The solution - store all thumbnails on my server. The first time one has to be served from the remote site (YT, Picassa etc.) so do that and then store it on your own site. Future times, you check if you have it and if so serve it always from your server. Cuts the page load time down to 2-3 seconds tops. Granted the first person to view the first home page load after someone has loaded more videos/images will take some time, but not thereafter. People will put a long one-off page load time down to their connection/the internet in general. Too many slow loads of your site and they will stop visiting!

I hope that helps somewhat.