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.
Choose whether nginx redirects the client or rewrites internally
An nginx redirect and an internal rewrite change different parts of the request flow. A redirect returns a status and Location for the client to consider, potentially causing a new request. An internal rewrite changes nginx’s current URI while processing the existing request. Choosing between them determines whether the client sees a new address, whether location selection runs again, and how the final handler receives path and query data.
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Measure the benefit of Redis pipelining
Pipelining reduces the waits between sending Redis commands, but its benefit must be measured for a particular workload. A remote synchronous loop may mostly wait for network latency; a local loop may spend more time in the client, scheduling, and socket I/O. Neither case justifies a universal promise of several-fold improvement.
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LATERAL lets each row open its own subquery
LATERAL lets a FROM item refer to columns from preceding items. It is useful when each parent needs a small, differently parameterized result, such as its two newest orders. The query remains one SQL statement and one database round trip, while the lateral expression states which outer values determine each result. It does not promise one particular physical execution strategy.
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Merge and rebase draw different history lines
Merge and rebase integrate work with different consequences for commit identity and ancestry. A merge normally retains the existing commits and joins their histories; a rebase transplants selected changes onto another base. The choice is not only how a graph looks. It affects review references, conflict handling, signatures, and collaborators who already depend on the old commits. Decide using the repository’s workflow and the actual branch relationships.
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An nginx prefix is a candidate until matching finishes
An nginx location selects configuration for a request within the chosen server. For the flat prefix and regex locations tested here, an exact match finishes the search; otherwise nginx remembers the longest matching prefix and can then choose the first matching regex. If no applicable regex wins, the remembered prefix supplies the configuration. This is a selection process, not simply the first block encountered in the file.
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pg_dump captures a consistent snapshot
pg_dump exports one PostgreSQL database using a consistent view of transactional data, even while other sessions commit changes. This prevents the ordinary table-by-table copy problem in which related tables reflect different committed states. The snapshot is only part of the backup contract: the archive must also be complete for its intended scope, readable by compatible tools, and successfully restored into a usable database.
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PostgreSQL time functions sample different moments
PostgreSQL offers several meanings of “current time.” A transaction timestamp identifies the beginning of a transaction, a statement timestamp identifies a command’s arrival, and a wall-clock reading samples the current clock during evaluation. Choosing among them changes the meaning of audit fields, expiration checks, and observations made during long-running work.
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Cron system and user tables have different contracts
Cron accepts schedules from more than one kind of table. A user crontab belongs to one account, while system tables can name the account for each entry. Copying a line between them without adjusting its fields changes what cron interprets as the command. Identify the table format before debugging an apparently correct five-field calendar expression.
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