Ace's Hardware Replaces PHP with Java. An interesting article that suggests some of the weaknesses of a naive PHP implementation for heavy traffic sites.
Here's what they should have done with PHP:
- Switched to using 2 web servers. One server for graphics, with Keep-Alives enabled, and another server for dynamic HTML using PHP and Keep-Alives disabled. This is an issue that occurs with all web servers, not merely PHP.
- Rewrite bits of their PHP using a HTML caching technology such as Smarty templates or PEAR Cache. This preserves their investment, and is a minor rewrite.
- Purchase Zend Accelerator.
You can read in the article that the main problem was the hardware could not keep up with the load. The new Java application performed poorly also the old hardware, and only when they upgraded to faster hardware did performance improve.
There are also pointers to where PHP needs to improve in the future: better resource pooling and multi-threaded support. [PHP Everywhere]