MariaDB Deadlocks in Small PHP Applications - Retry the Transaction, Not the Last Query
Two database transactions can each be valid on their own and still become unable to continue when they run together. One holds a lock the o…
RAG for Small AI Applications - Retrieve Evidence Without Treating It as Truth
RAG for Small AI Applications - Retrieve Evidence Without Treating It as Truth When a language model answers a question about a private do…
CORS for Small Web Applications - Decide Which Browser Origins May Read a Response
A browser console says that a request was “blocked by CORS.” The API may still return 200 OK in a terminal, and adding Access-Control-Allow…
systemd Service Watchdogs - Detect a Process That Is Alive but No Longer Progressing
A process can still have a PID, consume little CPU, and appear as active (running) while its useful work has stopped. Its event loop may be…
Foreign Keys in MariaDB - Let the Database Reject Impossible Relationships
A post row says its author is user 42, but user 42 does not exist. The application can hide the missing name, return an error, or quietly s…
Canonical URLs for Duplicate Pages - Make Every Signal Point the Same Way
One article can quietly acquire several addresses. A tracking parameter creates one URL, a print view creates another, and an old route may…
systemd Socket Activation - Let the Socket Wait Before the Service Runs
A service can be absent from the process list while its address is already listening. That sounds contradictory only if the daemon must own…
Post/Redirect/Get in PHP - Make Refresh Safe Without Pretending POST Is Idempotent
A form saves a new record, the browser shows a success page, and then someone presses refresh. Should that refresh display the result again…
HTTP Range Requests for File Downloads - Partial Content Is a Protocol, Not a String Slice
A large download stops halfway. The local file is still there, so asking for only the missing bytes sounds obvious. But what if the file be…
PHP OPcache During Deployments - Make Fresh Code Deliberate, Not Accidental
A deployment replaces PHP files on disk, but that does not by itself answer which compiled instructions a long-running PHP process will exe…