queues – Page 7 – Türker Yıldırım

Time-to-start per queue, as a metric

NoteJune 17, 20212 min read

Queue depth without throughput says nothing: a hundred jobs is fine at fifty a second and an incident at one a minute. Oldest-waiting-age is a direct measure of…

Queue priority is not a number, it is a separate queue

Deep diveJune 8, 202110 min read

Password resets stuck behind a nightly export. A priority field does not help when the worker is already four minutes into something else.

The outbox pattern, because two writes are not atomic

NoteJune 3, 20212 min read

Writing a row and publishing a message are two systems, and any ordering of them has a window where one succeeded and the other did not. Both writes…

A webhook endpoint that survives the sender

Deep diveJune 2, 202110 min read

The payment provider retried for six hours and every attempt timed out. A webhook is a notification, not a request for processing.

A saga is a compensation, not a distributed transaction

NoteMay 25, 20212 min read

A sequence of steps across services cannot be rolled back, so each step has a compensating action that undoes its effect after the fact. The compensations are business…

The service that should not have been a service

Deep diveMay 14, 202110 min read

Four services, three of which deploy together and share a database. The costs of distribution with none of the independence.

Kafka partitions are the parallelism limit

NoteMay 13, 20212 min read

A consumer group can have at most one consumer per partition, so the partition count is the maximum useful number of consumers. The inability to reduce the count…

Backpressure is the queue depth you agreed to refuse at

NoteApril 28, 20212 min read

A queue with no bound converts an overload into a latency problem that appears hours later and cannot be reasoned about. Framing the bound as a staleness budget…

A dead letter queue with nobody reading it is a bin

NoteApril 15, 20212 min read

Moving failed messages out of the main flow keeps the system healthy and does nothing on its own about the messages. The replay path is the part that…

Ordering is per partition, and only per partition

NoteApril 12, 20211 min read

Kafka guarantees order within a partition and nothing across partitions, which means the key choice is the ordering design. Choosing the key is choosing what is ordered relative…