Original, source-backed articles about running small systems, static sites, HTTP, DNS, TLS, and operations.
Posts are original articles written for this site. Each one is script-free, source-backed, and tied to the same operational reality the rest of the site records: how a small, static, publicly served system is built, secured, and kept honest.
WebSockets are a session, not a page
Most HTTP requests are one-shot: the client asks, the server answers, and the connection may end. A WebSocket upgrades a connection so either side can send at any time. Picking it over polling is a decision about whether updates should be pushed or fetched.
...
Prometheus histograms retain a bucketed distribution
A latency mean can conceal a slow subset of requests. A histogram retains more distribution information by counting observations into buckets, but it still discards detail within each bucket. Prometheus can estimate quantiles from those counts without storing every observation. The estimate depends on bucket boundaries and aggregation; it is not a recovery of the complete original latency distribution.
...
Passive upstream health follows failed traffic, not a probe timer
nginx passive upstream health uses outcomes of real requests to decide whether a peer should temporarily stop receiving traffic. max_fails sets an unsuccessful-attempt threshold, while fail_timeout supplies both the counting interval and the unavailability period. These settings do not schedule periodic application probes. Active checks require a supported checking capability and configuration beyond this passive request-outcome policy.
...
CDNs move the cache closer
A CDN can shorten the path between a reader and a reusable response, while reducing requests to the origin. Those benefits depend on routing, cache contents, and policy. A domain pointing at a CDN does not prove that an object is cached, that the geographically nearest machine serves it, or that every request avoids the origin.
...
A regular init container performs setup before a Pod’s application containers start. It has its own command, image and filesystem view, and can mount a volume that the application later reads. This separates a prerequisite from the main process, but does not make arbitrary setup safe or automatically bounded. Design the step around its actual retry behavior and the lifetime of its output.
...
A foreign key refuses to let a reference dangle
Adding a PostgreSQL foreign key to an existing table is both a schema change and a statement about old data. New writes can be checked immediately while historical rows still contain broken references. Separate the constraint’s enforcement, its validation state, and its checking time when planning a migration or diagnosing an unexpected integrity failure.
...
A purpose-built health check is worth keeping
A health endpoint is a contract with a consumer that will take action. Returning 200 because a handler ran does not prove that an instance can serve useful traffic. Before writing the endpoint, identify the decision it supports: allow initialization, admit requests, or restart a process that cannot recover. Different questions need different evidence.
...
Full versus incremental backups
A full backup provides a baseline without depending on an earlier backup from the same method. An incremental backup stores changes relative to a specified reference and depends on the material needed to reconstruct the omitted content. That distinction describes recovery dependencies, not a universal promise about speed or bytes transferred. A large changed working set can make an incremental backup substantial too.
...
