// a blog about systems that stagger but don't fall
Notes on resilience engineering, fault tolerance, and the endearing wobbliness of distributed systems that stagger under load and somehow keep walking forward.
WARN [render] section_alignment: off by 4px -- continuing
A monotonically-increasing counter is one of those things you take for granted -- until a kernel-level clock skew shoves your sequence numbers sideways and the queue starts handing out duplicate IDs to anyone who'll listen. Here's how we discovered it, why our retry logic actually helped, and what we wrote down so it never happens again.
read the whole thing →Every consumer that says "slow down please" is doing the rest of the pipeline a favour. We swapped a fire-and-forget producer for one that actually listens, and watched p99 latency drop by half. Pictures included, because backpressure deserves a comic strip.
read the whole thing →INFO [stack] recovering gracefully... lurching ahead
A bulkhead in a real ship looks intimidating: thick steel, heavy bolts, a vibe of do not approach. In code, it can be a twelve-line wrapper around a thread pool. We collect friendly versions of intimidating patterns -- circuit breakers that say sorry, retries with manners, timeouts with a sense of humour.
OK [hero] still standing -- proceed to next section
We deployed a config change. The config change had a typo. The typo looked like a flag. The flag was real. Reader, the flag was real.
full timeline →DNS didn't break. DNS just got slow. Slow enough that everything that depended on DNS got slow. We learned a lot about our own timeouts that day.
full timeline →The bartender says, "we don't serve your kind here." Then he serves it anyway, because the bar is a Linux box and Linux boxes have to serve everyone, even the leap seconds.
full timeline →WARN [grid] column_alignment drift +6px -- aesthetic intent
Because real systems don't glide. They lurch. They lean too far one way, catch themselves, lean back. The good ones make it look intentional. The great ones turn the lurch into a walking gait.
This blog is written by a small team of engineers who think the interesting part of distributed systems isn't the diagrams -- it's the moment the diagram gets it wrong and the system has to figure something out anyway. We collect those moments.
One letter, every other week. No tracking pixels. Frequently typo'd. Always free.
OK [footer] end-of-stack reached -- system stable