A Cache Hit Is Not a Freshness Guarantee

Tue, 01 Apr 2025 00:00:00 +0000

A catalogue price is cached at revision 1. The database commits revision 2. Three seconds later, Laravel finds the key and returns revision 1 from inside its declared five-second fresh window.

The cache hit is real. So is the stale price.

In the LAR-06 fixture , the cached JSON is well formed and its SHA-256 hash matches its body. Nothing has expired or become corrupt. The failure is semantic: current-price requires the acknowledged source revision, while the cache only knows that a key still contains bytes.

Cache the Deployment, Not the Assumption

Sun, 01 Dec 2024 00:00:00 +0000

Release B serves /inventory and labels its catalogue green. The code is correct. The environment is correct. Yet the application answers /catalogue with blue, while /inventory returns 404.

Nothing corrupted Laravel’s generated files. They contain release A’s configuration and route table because release A created them. The deployment combined those files with release B and produced a system which is consistently wrong.

config:cache and route:cache are often introduced as performance switches. That description misses their more important property: each command turns a set of inputs into a generated artifact. If the artifact is deployed, it must carry the same release identity as the code and environment which produced it.

Caching on Brian Faust

A Cache Hit Is Not a Freshness Guarantee

Cache the Deployment, Not the Assumption