Reliability and SRE
Reason about a service's reliability targets the way an SRE discipline does - set an SLO from the user's journey, compute the error budget it buys, and operate the service against that budget with burn-rate alerts, sustainable on-call, a toil cap, and the freeze that stops shipping when the budget runs out.
Units5
Duration29 min
Levelintermediate
By the end of this module, you'll be able to:
- Explain why reliability is engineered as a budgeted feature, not chased as an absolute, and why SRE is an engineering discipline rather than a renamed ops rota.
- Set an SLO from a critical user journey, pick the right tier target, and compute the error budget and burn rate it produces.
- State the error-budget policy - freeze on exhaustion, one named owner, security exempt - and say what it buys operationally: sustainable on-call, a capped toil load, tested resilience, and an SLA that is always looser than the SLO behind it.
- Read your org's reliability standard as the single source of truth for a service's reliability posture - Cogitave records its own in reliability.md and ADR-0020 - and know when a different value requires an Accepted RFC.
Prerequisites
- Completion of "Work the request lifecycle", or equivalent familiarity with your estate's propose-only change process.
- Familiarity with SLIs and telemetry is helpful; this module defines SLO and error budget from first principles.
Units
- 01Introduction4 min
- 02SLOs and error budgets8 min
- 03Operating for reliability9 min
- 04Knowledge check5 min
- 05Summary3 min
Related
- Operate from Day 1 Describe the Day 1 operating model - the pinned inner loop and the flow-based outer loop - state the parity contract that keeps the inner loop honest, read Cogitave's flow-based ways of working and its ADR-0025 choice of flow over Scrum as one org's answer, and explain why the human gate stays an exception inside the flow.
- Respond to incidents Walk the incident-response flow end to end - detection, severity declaration, single-commander roles, containment through a runbook, communication, recovery, and the blameless postmortem - and see how business continuity and disaster recovery extend the same discipline to a region loss or a destructive event.
- Run agentic operations Explain what agentic operations means - agents running an estate unattended inside rails - state the draft-vs-act rule that decides when an agent acts unattended versus when it stops for a human, and study Cogitave's own fleet of scheduled and operations agents as the worked example of the fleet you would build.