What a Write-Ahead Log Actually Promises
The durability primitive underneath every database, and the one number that shapes every decision in it.
#distributed-systems
7 posts
Tracing a Job That Outlives Its Request
Parent and child is a claim about containment. Queued work isn't contained by anything, so it needs a different relationship.
The Load Test That Was Supposed to Fail
173,000 requests with zero errors told me nothing useful. The test that broke its own thresholds told me everything.
What 'Processing' Means When the Worker Is Gone
A status column records what a job was doing. It cannot record whether anyone is still doing it.
Retries, Backoff, and Why Jitter Is Not Optional
Retrying is easy. Deciding when to retry, and making sure everyone doesn't decide the same thing, is the actual work.
Two Stores, One Job, and the Gap Between Them
Splitting durable truth from fast dispatch buys a lot. It also creates a dual write I never made atomic.
Why I Didn't Just Use Celery
A job queue is a promise that work you accepted will eventually happen. Making that promise honestly is the hard part.