Engineering for Reliability
Getting started with SLOs
Twenty-three substantive episodes on SLOs, telemetry, alerting, investigation, and operations
Twenty-three 2021–2022 episodes connect user-facing reliability targets to metrics, logs, traces, and alerts. Examples show instrumentation, Prometheus collection, quota monitoring, GKE investigation, and observability cost controls.
In this collection Browse 23 summaries 20 of 23
Saying a service is “up” does not explain whether users can successfully use it. This episode introduces service-level indicators (SLIs) to measure successful interactions and service-level objectives (SLOs) to set reliability targets. It treats reliability as a feature to plan and measure alongside other product work 00:00–04:12(opens in a new tab).
Key Points Covered
- Service type shapes the objective: Applications and APIs need to be available and responsive. Data pipelines also need to process data correctly and move it through the pipeline quickly enough for their users 00:00–02:05(opens in a new tab).
- Define what counts as success and what counts at all: The example's availability SLI divides successful HTTP 200 responses by total valid requests. Excluding HTTP 400 responses believed to come from misconfigured clients is a deliberate choice, not an automatic property of the metric 02:05–04:12(opens in a new tab).
- Set a target that reflects user needs: An SLO combines the indicator, a threshold, and an evaluation period. The presenter recommends the level at which typical users are just satisfied: once that need is met, additional engineering effort might be more valuable in new features than in exceeding the reliability target 03:07–05:14(opens in a new tab).
- Do not confuse a budget reset with improved reliability: The error budget tracks room for failures while meeting the target. A calendar period restores the whole budget at rollover even if the service has not improved. A rolling window avoids that one-time reset, which is why the presenter warns about calendar-based budgets 05:14–07:21(opens in a new tab).
Full video: https://www.youtube.com/watch?v=U53wC2A75Is(opens in a new tab)