Caching

On 7 September we went looking at customer/section/load on a stock Magento 2.4.8 store with the sample data. It’s the request that fills in everything a cached page can’t know about you: your name, your cart count, your messages. It can never be cached, so every call boots the whole application. One response was 61,194 bytes. About 59 KB of that was directory-data: every country and every region the store knows. The same list for every visitor on the planet, travelling through the one channel in Magento that exists because responses can’t be shared. ...

In July 2012 I wrote a post called Varnish implementation hints and good to know. It opens with “Sharing knowledge is always a good idea,” and then shares, in order: a set of bash aliases that switch Varnish on and off with iptables, a header that tells PHP whether Varnish is in front, a cookie-stripping regex, a one-line purge, and what it calls “a favorite of mine”, a function that walks every URL in the sitemap so you can clear them all. ...