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.
Redis Pub/Sub broadcasts without replay
Redis Pub/Sub broadcasts to subscriptions that are active when a message is published. It does not retain an inbox for a disconnected listener. This suits replaceable live notifications, but a positive PUBLISH response is not evidence that a worker finished a job or that an offline consumer can recover it.
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A here-string supplies text and a newline
A Bash here-string supplies the expanded value of one word to a command’s standard input, with a newline appended. It is convenient when a small textual value already exists in a variable and the receiving tool reads stdin. The syntax removes the need for a separate printing command, but it does not promise byte-for-byte identity with the variable or a particular implementation using memory, a pipe, or a file.
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A pool shares a few Postgres connections among many requests
A connection pool lets many application requests borrow a smaller number of PostgreSQL sessions over time. Reuse amortizes connection setup and limits simultaneous leases, but does not make an overloaded database faster by itself. The pool creates another queue whose capacity, waiting time, and cancellation behavior belong to the request budget. Treat that queue as part of the service, not as an invisible implementation detail.
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Semantic versioning makes compatibility explicit
A dependency version is useful when its publisher and consumers agree on the public contract. Semantic Versioning gives changes a vocabulary: from version 1.0.0 onward, incompatible public API changes require a major increment, compatible additions require a minor increment, and compatible fixes require a patch increment. The number summarizes a claim about a release. It does not inspect its implementation or guarantee that an upgrade will work in your application.
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Basic auth carries a reusable credential
HTTP Basic authentication places an encoded username and password in an Authorization header. The encoding is reversible, so possession of that header can be equivalent to possession of the credential. Basic defines a challenge-response exchange, but it does not cryptographically bind a response to a fresh server nonce. A captured accepted value can be replayed while the server continues to accept that account and credential.
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A Service gives a pod a stable virtual address
The selector turns the Service from a fixed Endpoint into a live view: refresh happens in the background, and a client never edits its config when pods restart.
Declared, then given an address An ordinary ClusterIP Service provides a virtual address and, with cluster DNS, a stable discovery name for its lifetime. A selector-based Service also declares which Pods in its namespace are intended backends. Other forms differ: headless Services allocate no virtual IP, ExternalName uses DNS indirection, and selectorless Services can use separately managed EndpointSlices.
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Feature flags decouple release from exposure
Deploying code and exposing it are different acts. A feature flag can select a runtime path after the code is deployed. This supports gradual exposure and fast disablement, provided the old path remains compatible and the configuration reaches the processes that evaluate it. The flag controls a decision; it does not reverse everything the deployment or the new behavior has already done.
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Choose B-tree or hash from the required operations
PostgreSQL’s default B-tree index supports several common query requirements: equality, ranges, ordered access, and uniqueness enforcement. A hash index supports a narrower equality access path. Choosing between them starts with the required operators and constraints, then proceeds to measurement. Saying that hashes are always faster for equality, or that PostgreSQL almost never chooses them, replaces a workload question with an unsupported generalization.
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