A multi-stage Dockerfile can serve development and production from one file, provided the build is told where to stop. The last form is the one worth remembering, because…
CPU, memory and disk are causes, and there are unlimited causes — most of them entirely compatible with a healthy system serving every request correctly. The test for…
A reload starts new workers with the new configuration and lets the old ones finish their current requests, so an nginx process list after a reload legitimately contains…
The aggregate boundary is not a modelling preference — it is the answer to which invariants have to hold at every instant, and everything else can be eventually…
Mounting /var/run/docker.sock into a container to let it build images is equivalent to giving that container root on the host, and it is presented in most CI documentation…
On a multisite network the object cache prefixes keys with the blog id unless the group is declared global, so data cached on one site is invisible to…
A timer that has been scheduled and has never actually renewed anything is untested code with a deadline, and the first sign of trouble is a browser warning.…
Routing failed messages somewhere they cannot block the main queue is correct design, and it converts a loud failure into a silent one unless something watches the depth.…
7.0 changed the default primary shard count from five to one, which is a considerable behavioural change hidden in a release note. The old default was widely agreed…