We added ePHPm to the Yii3 runtime benchmark. It runs the same Yii3 API app on a bunch of PHP runtimes and compares them. Our fork with the ePHPm runner is ephpm/app-api.

Of the three platforms ephemerd runs jobs on, Linux has the weakest isolation. Windows jobs get a Hyper-V isolated container with its own kernel. macOS jobs get a whole VM. A Linux job is an ordinary runc container sharing the host kernel. A kernel escape from a Linux job is a host compromise. Kata Containers fixes that by putting each container in a lightweight VM with its own kernel. It plugs into containerd as just another runtime handler. So I added it in #155, measured it, and left it off…

litewire is the piece of ePHPm that lets PHP apps talk MySQL to a SQLite file. I wrote about how it works and about the MySQL quirks WordPress depends on. This one is the less visible half of August:

Every PHP deployment I’ve run eventually grew a Redis. Sessions, the WordPress object cache, Laravel’s cache and locks, rate limiting. ePHPm is supposed to be one binary that replaces nginx + php-fpm + Redis, so it needed a cache in the box. I didn’t want to write one. This post covers why I did anyway and how it’s built. It also covers the bug that sat in its eviction code from March until last month. Then I compare it against a stock Redis on the same machine with…

PHP’s share-nothing model is one of its best properties. It has one expensive side effect: a request can’t keep a database connection for the next request. php-fpm gives you PDO::ATTR_PERSISTENT and mysqli’s p: hosts. But those are per-worker-process. PDO’s keep whatever session state the last request left behind. mysqli at least resets the session with COM_CHANGE_USER on reuse. And almost nobody turns them on. So in practice every PHP request does a TCP connect, a MySQL…