performance – Page 32 – Türker Yıldırım

Apdex, and a number somebody outside engineering can read

NoteFebruary 13, 20202 min read

A p99 in milliseconds means nothing to somebody who does not think in latency distributions, and Apdex compresses the same data into a number between zero and one.…

useMemo is a hint, not a guarantee

NoteFebruary 4, 20201 min read

The documentation says React may discard memoised values to free memory, and code that treats useMemo as a cache with a guarantee is relying on something that is…

Blade components and the partial that had eleven parameters

Deep diveJanuary 8, 202010 min read

An @include with eleven variables and no way to know which are required. A partial is a file rather than a contract, and 7.0 makes the constructor the…

Weak references, and the cache that stops leaking

NoteDecember 30, 20192 min read

A registry keyed by object identity keeps every object it has ever seen alive, so a long-running worker’s memory grows in proportion to the number of distinct objects…

Typed properties and the constructor that got shorter

Deep diveDecember 25, 201910 min read

7.4 landed on 28 November and the docblock is no longer the only type. Uninitialised is a new state, and arrow functions remove the use() clause.

innodb_buffer_pool_size is the one setting that matters

NoteNovember 25, 20191 min read

Almost every MySQL tuning guide lists forty variables, and on a dedicated server the first one accounts for most of the difference — it is the cache that…

The dependency array is not a list of things to watch

NoteNovember 19, 20192 min read

It reads like a watch list and it is not. It is a declaration of everything the effect closes over, and the effect re-runs whenever any of them…

A nginx map is a lookup table that beats a chain of ifs

NoteNovember 13, 20192 min read

if inside a location block is famously unreliable in nginx, and a chain of them for what is really a lookup is both slow and surprising. A map…

rest_pre_dispatch, and short-circuiting a request cheaply

NoteNovember 11, 20192 min read

A rate limit, a maintenance mode or a global authentication check placed inside every route callback is a check repeated forty times; the dispatch filter runs once. Returning…

TypeScript on a JavaScript codebase, one file at a time

Deep diveNovember 8, 201910 min read

3.7 shipped optional chaining in November and the objection got smaller. allowJs, checkJs and a per-file opt-in — and strictNullChecks, which is the flag that pays.