Intermediate everything in DevOps & Cloud, page 5
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…
Auto-Instrumentation
Auto-instrumentation automatically adds telemetry to an application without manual code changes, by hooking into libraries, frameworks, or the runtime. It gives broad baseline observability fast, but produces generic spans that often need manual…
Metrics in Observability
Metrics are numeric measurements aggregated over time, like counters, gauges, and histograms. They are cheap to store and fast to query, making them ideal for dashboards and alerting, but their pre-aggregation discards per-event detail needed for deep…
Observability vs Monitoring
Monitoring watches predefined metrics and alerts on known failure modes you anticipated. Observability is the property of being able to ask new questions about a system's internal state from its outputs, letting you debug unknown failures you never predicted…
Alerting on under-replicated Deployments
Write an alerting rule comparing kube_state_metrics available vs desired replicas with for: 5m, Prometheus evaluates and fires to Alertmanager, which dedupes/routes/notifies.
PromQL for top 5 CPU-consuming pods
Apply rate() to the counter over 15m, sum by pod to combine containers, then wrap in topk(5); rate handles counter resets.
EFK centralized logging architecture
Fluentd runs as a DaemonSet collecting node container logs, parses and forwards to Elasticsearch for indexed storage, and Kibana queries and visualizes them.
Auto-discovering app pods for Prometheus scraping
Use kubernetes_sd_configs with role pod, relabel on pod annotations like prometheus.io/scrape to filter, and set path and port; with the Operator use a PodMonitor or ServiceMonitor.
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