queues – Page 11 – Türker Yıldırım

Serialising an object with a closure in it, and why it fails

NoteSeptember 17, 20192 min read

A closure has no serialisable representation in PHP, so any object holding one — a validator with a custom rule, a collection with a lazy callback — cannot…

Consumer groups distribute; a plain read does not

NoteSeptember 8, 20191 min read

Reading a Redis stream directly gives every consumer every entry, which is right for fanout and wrong for a work queue. The > means entries never delivered to…

Job middleware, and the rate limit that is not in the handler

NoteAugust 17, 20192 min read

A job that must not run more than once per minute per customer had that logic at the top of handle(), mixed with the work, and repeated in…

A dead letter queue with no alert is a bin

NoteAugust 6, 20192 min read

Routing failed messages somewhere they cannot block the main queue is correct design, and it converts a loud failure into a silent one unless something watches the depth.…

A delayed message is a broker feature, not an application one

NoteJuly 24, 20191 min read

Scheduling work for later by storing a row and polling it is a scheduler you now maintain, and every broker worth using has a delay mechanism already. The…

The queue worker that leaked, and the memory limit that hid it

Deep diveJuly 15, 201910 min read

A worker restarting every eleven minutes, reported as healthy. Finding the leak is not the same as bounding it, and the seatbelt hides the next one.

Messenger, and the queue that is part of the framework

Deep diveJune 25, 201910 min read

4.3 made Messenger stable, and dispatch stopped being the same decision as transport. A message, a handler, and routing declared in configuration.

Lazy collections and the report that would not fit in memory

Deep diveJune 24, 201910 min read

A memory limit hit on the fourth of the month, every month. A collection is an array, and an array is all of it at once — until…

A Messenger handler is a callable with a type hint

NoteMay 21, 20192 min read

4.3 made Messenger stable, and the registration mechanism is autoconfiguration on an interface — so a handler is a class with one method and no boilerplate. The message…

Trimming a stream approximately, because exactly is O(n)

NoteMay 14, 20191 min read

A stream does not empty itself, and exact trimming has to walk to find the boundary — which on a large stream is a foreground operation on a…