sheego.de, like most e-commerce platforms, is in a perpetual state of growth. Ensuring this growth requires constant technical improvements to keep boosting performance and stability. sheego.de, a German online fashion clothing mail-order company, which specializes in mail-order fashion for women sized 40 (UK size 16) and up, adopted Varnish Plus as its caching and performance component as it moved to the open-source, PHP-based OXID eShop framework.
Quite a while back, I wrote the first part of this blog series about the challenges of cache invalidation with the dispatcher in Adobe Experience Manager 6.0 and Adobe CQ 5.x in any Linux platform (Adobe supports Red Hat running a Linux Kernel 2.6 and 3.x). So the context should be clear. But how do you actually go about replacing it?
To help ensure our customers and fans continue to discover the right products for the right job, we’ve made a few changes. The product formerly known as Varnish Hashninja will hereby be known as Varnish Enhanced Cache Invalidation.
“There are only two hard things in Computer Science: cache invalidation and naming things.” -- Phil Karlton
Today, I’ll write about the hardest one of these two; cache invalidation. This used to be rather straightforward. Most websites had a rather simple structure between their content repository and their URL structure. This made it rather simple to purge URLs when the content changed.