GuideTechnology
14 min read
If you cannot observe a system, you cannot operate it. Learn the three signals (structured logs, metrics and distributed traces), the golden signals and RED and USE methods, percentiles and histograms, trace context propagation and OpenTelemetry, SLIs, SLOs and error-budget alerts, health checks and synthetic monitoring, and how to observe asynchronous systems without drowning in data.
GuideTechnology
14 min read
How systems survive failures of servers, availability zones and whole regions, and recover from data disasters. Covers failure domains, redundancy and failover, availability arithmetic with correlated failures, RPO and RTO, the four disaster-recovery strategies from backup-and-restore to active-active, multi-region write strategies, backups that actually restore, and safe deployments.
GuideTechnology
16 min read
How one slow dependency takes down a whole system, and the techniques that stop it: timeouts and deadlines, retry budgets, circuit breakers, bulkheads, rate limiting, load shedding, backpressure and graceful degradation, with a runnable circuit breaker and a degradation plan for a real page.
GuideTechnology
17 min read
Retries are necessary in distributed systems, and they create duplicates. Learn what idempotency means, where duplicates come from, how to build idempotency keys correctly, unique constraints and idempotent consumers, which errors to retry, exponential backoff with jitter, retry amplification, and what at-most-once, at-least-once and effectively-once delivery really promise.
GuideTechnology
14 min read
What changes when work is spread over many machines: partial failure, messages that are lost, delayed, duplicated or reordered, timeouts with unknown outcomes, process pauses, and clocks that disagree. Learn why a timeout does not tell you what happened, why wall clocks cannot order events, how logical clocks help, and the design habits that follow.
