Intermediate everything in Monitoring & SRE, page 4
Why use latency percentiles over the average?
Averages hide the tail and are skewed by outliers, so most users can suffer while the mean looks fine; use percentiles; prioritize p99 when tail users are high-value or fan-out…
What makes a blameless postmortem effective?
Cover summary, impact, timeline, root cause, action items; explain blameless means focusing on systemic causes so people report honestly.
How do you find and eliminate toil systematically?
Inventory and measure toil via time tracking or ticket analysis, prioritize by frequency times cost versus automation effort, automate highest-ROI items, measure success…
Error budget exhausted early: what now?
Invoke the error budget policy, shift focus from features to reliability, prioritize stability work, analyze what burned the budget.
How do you set SLOs for a service from scratch?
Identify critical user journeys, pick SLIs that reflect user happiness, measure current performance, set achievable targets with buffer, iterate.
Normalization of Deviance
Normalization of deviance is the gradual process by which unsafe practices become accepted as normal because they have not yet caused a visible failure. Each tolerated shortcut lowers the bar, eroding safety margins until a catastrophe finally results.
Hiring for SRE
Hiring for SRE seeks engineers who blend software-development skill with systems and operations depth, plus strong debugging and incident temperament. The hardest part is finding people who can both write automation and reason about failure at scale under…
LitmusChaos
LitmusChaos is an open-source, Kubernetes-native chaos engineering platform that runs fault experiments as custom resources. It injects failures like pod kills, network latency, and resource stress to validate that services stay resilient under real-world…
Backpressure
Backpressure is a mechanism by which a slow consumer signals an upstream producer to slow down or stop, preventing unbounded queues and resource exhaustion. It keeps systems stable under overload by propagating capacity limits backward through a pipeline.
Performance Profiling
Profiling measures where a program actually spends its time and resources, attributing CPU cycles, memory, or wall-clock latency to specific functions or call paths. It replaces guesswork with data so optimization effort targets the real bottleneck.
Review of Reviews (Postmortem Metrics)
A meta-process that audits the quality and follow-through of postmortems themselves, tracking metrics like action-item completion, time-to-close, and recurrence of incidents.
The Second Story of an Incident
The first story blames human error and stops there; the second story asks why the action made sense to the person at the time and what systemic conditions enabled it. Seeking the second story is the heart of blameless, learning-oriented incident analysis.
Counterfactual Reasoning in Incident Analysis
Counterfactual reasoning asks what would have prevented or mitigated an incident: if this alert had existed, if this check had run. Used well it finds systemic gaps, but it is a trap when it implies a single person should have just acted differently in…
Actionable Remediation Items
Actionable remediation items are specific, owned, trackable follow-ups from a postmortem that prevent recurrence or improve response. Good ones are concrete and assigned with a due date; vague items like be more careful are non-actionable and predictably…
Postmortem Report Template
A postmortem template is a standard structure for documenting an incident: summary, impact, timeline, root cause, what went well and poorly, and action items.
Incident Timeline Reconstruction
Timeline reconstruction is the after-the-fact process of merging evidence from logs, metrics, deploys, and chat into one accurate sequence of what happened.
War Room in Incident Response
A war room is a dedicated space, physical or virtual, where responders coordinate during a major incident. It centralizes communication and decision-making under a defined incident commander, cutting confusion and duplicated effort, but should be reserved for…
Runbooks
A runbook is a documented, step-by-step procedure for handling a specific operational task or known failure, such as responding to an alert. It captures expert knowledge so any on-call engineer can act quickly and consistently, reducing reliance on tribal…
Incident Timeline
An incident timeline is a chronological, timestamped record of what happened during an incident: detection, key events, actions taken, and resolution. It anchors the postmortem in facts, separates symptoms from causes, and reveals detection and response…
Baggage in Distributed Tracing
Baggage is key-value context propagated alongside a trace across service boundaries, so downstream services can read values set upstream. It enables cross-cutting context like tenant id, but it travels in headers on every hop, so overuse adds latency and leak…
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