This two year old post about Rasmus Lerdorf’s PHP scaling tips (slides) is interesting in the context of what we’ve learned since then. APC now seems common, and it’s supposedly built-in to PHP6. Still, I’d be interested in seeing an update. Are MySQL prepared statements still slow?
And that’s where Rasmus’ latest presentation comes in. We don’t learn anything about MySQL prepared statements, but we do learn how to find choke points in our applications using callgrind and other tools. In his examples, he can do a little over 600 transactions per second with both static HTML and simple PHP, but various frameworks — with many inclusions and function calls — can slow that to under 50 transactions per second (I suppose they’d explain that in a TPS report).