CPU Usage Doubled Upgrading from 2.7.3 to 2.8.1

Question

We recently upgraded from 2.7.3 to 2.8.1 and our Apache/PHP CPU usage has skyrocketed. MySQL usage has stayed about the same... no notable impact there, but we're definitely chewing more processing time with PHP.

We updated all of our add-ons, etc., separately so I think the only thing that changed in concert with the CPU load is the actual EE Core to 2.8.1.

Anything in there that would cause this? We use eAccelerator and that's still running and caching all the new scripts, but it sure seems like it's not running. That or, more likely, something else is just not jiving right.

Any thoughts?

Thank you!

Answer 1

This may not be the problem but you should definitely get rid of eAccelerator. It's flaky with some PCRE operations (using preg_match() for example) in PHP 5.4 and later. It's possible code changes in EE or one of the add-ons you use have triggered a bug. Use Zend Opcache instead on PHP 5.4+.

Other than that, upgrading to EE 2.9 would likely give you back some performance due to the new conditional parser.