sreopsincident-response

Operational Playbook: Monitoring and Incident Response During Peak Streaming Events

mmanuals

2026-02-11

11 min read

An SRE playbook for peak streaming events: SLIs, alert thresholds, runbooks, rollback commands and communication templates for live events.

Hook: Why this playbook matters now

Peak live events (sports finals, mass e-commerce drops, political debates) turn platform weaknesses into visible disasters in seconds. As an SRE running a streaming platform you face fragmented telemetry, unpredictable client behavior, and zero-tolerance SLAs while leadership, legal, and media demand clear answers. This playbook gives an operational, step-by-step approach—pre-event readiness, monitoring thresholds, runbooks, rollback commands and communication templates—so you and your team can prevent scale problems and resolve incidents quickly when they occur.

Executive checklist: what to prepare before game day

Define SLIs & SLOs for key user journeys (start, play, seek, DRM, ad insertion) and agree on severity tiers with business owners.
Run capacity smoke tests and worst-case load tests (real client SDKs, not just HTTP floods).
Multi-CDN and fallback plans validated (<15s DNS/Edge switch paths documented).
Feature flags ready to toggle decoupled UI/UX and server-side features.
Pre-warmed infra (transcoders, origin caches, edge workers) and reserved capacity with cloud/CDN partners.
Communication templates (internal, status page, customer) pre-approved by comms/legal.
On-call roster & escalation matrix published with contact methods and replacement rules.
Runbook snippets for the top 6 failure modes (CDN 5xx, origin overload, encoder backlog, DRM failures, manifest errors, player rebuffering).
Tabletop rehearsal 48–72 hours before the event with triage and comms practice.

Monitoring: SLIs, SLOs and practical alert thresholds

Accurate monitoring is the core of fast incident response. Focus on a small, high-fidelity set of SLIs that represent the end-user experience and map them to SLOs and concrete alert thresholds. Use a mix of Real User Monitoring (RUM), synthetic checks, CDN telemetry, and server-side metrics.

Key SLIs for streaming platforms (recommended SLOs & thresholds)

Stream Start Success Rate (SSSR): SLO 99.95% (VIP) / 99.5% (global). Alert: warning if 99.9% over 5m, critical if <99.5% over 5m.
Startup Time (time-to-first-frame): SLO median < 2s. Alert: warning if P90 > 4s, critical if P90 > 6s.
Rebuffering Ratio (rebuffer secs / play secs): SLO < 0.5%. Alert: warning if > 1% on 5m window, critical if > 2%.
Video Error Rate (player fatal errors / plays): SLO < 0.1%. Alert critical at > 0.5%.
Manifest/Playlist Failures: SLO 99.99% success. Alert immediate on any manifest 5xx or 404 spike > 0.1%.
CDN Edge 5xx Rate: Alert warning if > 0.5% across edges; critical if > 2% or concentrated in a major POP.
Encoder/Transcoder Queue Depth: Alert warning if queue > 50% of buffer; critical if queue > 80% or processing lag > 30s.
Origin Latency / Error Rate: Alert if P95 origin latency > 500ms or error rate > 1%.
Auth/DRM Failures: Alert immediate on any elevated auth failure rate impacting playback (lockouts are high-severity).

Alerting best practices

Prioritize actionability: Each alert must have an owner and a runbook link. If it’s noisy and not actionable, disable or refine it.
Composite & burn-rate-based alerts: Use SLO burn-rate-based alerts for business-facing pages—trigger escalations when burn-rate exceeds thresholds (e.g., 14x in 5m).
Multi-window rules: Combine short-window severity for fast triage (5m) with long-window detection (1h) to catch slow degradations.
Suppression windows: Temporarily suppress non-critical alerts while executing a major mitigation with a documented “suppress until” to avoid alert storm fatigue.
Client-side telemetry: Enrich server signals with RUM to validate user impact before broad escalations.

# Example Prometheus alert for Stream Start Success Rate (SSSR)
  - alert: StreamStartSuccessRateLow
    expr: (sum(rate(stream_start_success_total[5m])) / sum(rate(stream_start_attempt_total[5m]))) * 100 < 99.5
    for: 2m
    labels:
      severity: critical
    annotations:
      summary: "SSSR below 99.5% ({{ $value }})"
      runbook: "https://runbooks.internal/sssr"

Runbooks: step-by-step actions for the top incidents

For each high-priority alert, maintain a short runbook with a clear triage flow: Detect → Triage → Contain → Mitigate → Verify → Postmortem. Below are condensed operational runbooks for common failure modes.

Runbook: CDN Edge 5xx Spike

Detect — Alert fires: CDN 5xx > 2% or concentrated in major POP.
Triage — Check edge geography, POP metrics, and upstream origin error rates. Determine if 5xx is edge-only or origin-propagated.
Contain — If origin errors are low, shift traffic away from affected POPs via multi-CDN control-plane or faster edge routing rules. If using Fastly/Cloudflare, apply emergency edge-routing override.
Mitigate — If origin is overloaded: enable increased caching TTLs, serve stale-if-error where safe, escalate to scaling team to add origin capacity. If edge bug: roll back recent CDN configuration changes or WAF rules.
Verify — Confirm SLR (stream-level recovery) via RUM/Synthetic checks and monitor 5xx fall back to baseline.
Postmortem — Capture timeline, config deltas, and corrective action.

Runbook: High Rebuffering / Player Rebuffer Spike

Detect — Rebuffering ratio alert fires; check client metrics by region & ISP.
Triage — Correlate with CDN errors, manifest changes, encoder delays, and network packet loss signals.
Contain — Reduce ABR ladder by disabling highest bitrates via manifest rewrite or feature flag to decrease throughput needs; enable aggressive CDN caching for segments.
Mitigate — If CDN-side, shift to alternate CDN/POP. If origin-side or encoder backlog, increase transcoder capacity or temporarily serve VOD/low-res fallback.
Verify — Validate RUM median startup and rebuffer metrics improved within 5–15 minutes.

Runbook: Transcoder/Encoder Backlog

Detect — Encoder queue length exceeds threshold or processing latency exceeds real-time window.
Triage — Identify if backlog is caused by input bitrate surge, VM/CPU exhaustion, or faulty encoder process.
Contain — Throttle incoming ingest via upstream load-shedding policy or route new sessions to standby encoders. Activate warm standby clusters.
Mitigate — Scale transcoder fleet (auto-scaling groups or K8s HPA), switch to less CPU-intensive presets, or drop to single-pass encoding for live segments to reduce CPU.
Verify — Confirm segment generation within target latency and that downstream manifests are updated.

Runbook: Manifest/Playlist Failure (404/500)

Detect — Manifest error rate > 0.1% or customer reports of inability to play.
Triage — Check recent deployment of manifest generator, storage permission changes, or CDN purge jobs.
Contain — Roll back manifest generator deployment, restore last-known-good manifests from storage, or route clients to alternate manifest URL.
Mitigate — If caused by a build, execute a fast rollback (artifact-based). If due to object storage permission, revert IAM policy and re-deploy manifests.
Verify — Confirm manifest availability via synthetic tests and that player health improves.

Rollback plans & command cheatsheet

Every deployable subsystem needs a documented rollback action that can be executed with minimal context. Keep rollbacks reversible and ensure DB schema changes are backward compatible before the event.

Generic Kubernetes rollback (example)

# Roll back a deployment to previous revision
  kubectl rollout undo deployment/streaming-service -n live-event
  # Verify
  kubectl rollout status deployment/streaming-service -n live-event --watch=false

Feature flag quick disable (example using LaunchDarkly CLI)

# Turn off a flag immediately
  ldctl toggle set --env production --flag reduce_quality_for_event --value false

CDN failover (example Command-line snippets)

# AWS Route53: switch alias to backup origin
  aws route53 change-resource-record-sets --hosted-zone-id ZABCDEFG --change-batch file://switch-to-backup.json

# Cloudflare API: Purge and route
  curl -X POST "https://api.cloudflare.com/client/v4/zones/{zone}/purge_cache" -H "Authorization: Bearer $TOKEN" --data '{"purge_everything":true}'

Escalation matrix & communication templates

Incidents are social as much as technical. Define clear escalation roles: Incident Commander (IC), Tech Lead, SRE Responder, CDN Liaison, Comms Lead, Legal. Use short, consistent templates for all status updates.

Escalation flow (example)

Alert → Primary on-call SRE for 5m
No resolution → Escalate to Tech Lead / IC at 5–10m
Business-impacting (burn-rate or customer-visible outage) → Notify Comms & Execs at 10–15m
All hands → Assemble cross-functional bridge at 15–30m

Internal Slack/Chat template

:rotating_light: INCIDENT: {{short-summary}} | Severity: {{sev}} | Impact: {{#users}}major region{{/users}}

Affected services: {{services}} | First detected: {{time}} UTC | IC: @{{ic}} | Bridge: {{bridge-link}}

Current action: {{what-we-are-doing}} | Next update: in 5m | Runbook: {{runbook-link}}

Customer-facing status update (short)

We are aware of playback interruptions for some viewers and are actively working on mitigation. Our engineering team is investigating and we will provide an update within 10 minutes. We apologize for the disruption.

Status page message (progressive updates)

Initial: Identified playback degradation. Triage in progress.
Mitigation in progress: Implementing CDN reroute / reducing bitrate ladder.
Resolved: Restored normal service at {{time}}. Postmortem in progress.

Testing & rehearsal: how to validate readiness

Tabletop drills: Run a 60–90 minute scenario with comms and execs. Validate templates and chain-of-command.
Load testing with real SDKs: Simulate player behavior, ABR switching and network churn. Use geographically distributed agents.
Chaos experiments: Conduct planned chaos on non-prod (fail an edge, throttle an origin) to verify fallback logic and automation.
Synthetic canaries: Deploy low-latency synthetic checks for pre-roll and mid-stream checks to detect degradations in under 30s.
RUM sampling & privacy: Ensure RUM telemetry samples are compliant with privacy regulations and instrumented to quickly slice by region, device, and CDN.

Postmortem: structure for fast learning

A high-quality postmortem must be blameless, time-bound, and include actionable follow-ups. Include an executive summary and impact metrics up front so stakeholders can quickly understand the business effect. For guidance on quantifying business loss from outages, see Cost Impact Analysis.

Postmortem template (essentials)

Summary: What happened and user impact (minutes, percent affected, streams lost).
Timeline: minute-by-minute detection, mitigation and resolution actions with owners.
Root cause: Primary technical failure and contributing factors.
Corrective actions: Short-term and long-term items with owners and deadlines.
SLO impact: SLI/SLO breach details and burn metrics.
Preventative measures: Monitoring, runbook, and architectural changes to prevent recurrence.

Advanced strategies & 2026 trends that should influence your playbook

Live streaming operations evolved quickly in late 2024–2025 and into 2026. Here are practical trends to incorporate into your playbook.

Edge compute and workers: Use edge logic for manifest stitching, ABR hints, and ad insertion to reduce origin pressure. Pre-test edge scripts and keep quick rollback routes for edge logic changes.
AI-driven anomaly detection: AIOps models can detect complex patterns earlier than static thresholds. Use them as augmenting signals, not the only source of truth—always tie to an SLI.
Dynamic SLOs & burn-rate automation: Automate escalations via SLO burn-rate rules during events so human attention is focused where it matters most.
WebRTC / LL-HLS prevalence: Low-latency streaming adoption increases complexity—ensure your encoders and player telemetry capture latency metrics separately.
Multi-CDN orchestration: Dynamic routing by geography, ISP and cache-hit success will be table stakes. Contractual pre-warm and surge SLAs are critical for sports events.
Client-side telemetry privacy: Regulations in 2025–2026 tightened telemetry collection; implement privacy-preserving RUM and ensure sampling strategies are documented.
Serverless and ephemeral transcoders: On-demand encoding systems allow fast scale but require testing for cold-start latencies and resilience of backing stores. Vendor and cloud partner risk should be part of your pre-event assessment.

Compact quick-reference playbook checklist

Pre-event: SLO sign-off, capacity smoke, flippable feature flags, pre-approved comms.
Monitoring: Ensure SSSR, Startup Time, Rebuffer ratio, CDN 5xx alerts are green; run synthetic canaries.
On-alert: Attach runbook, assign IC, and post initial internal message within 2 minutes.
Mitigation: Execute prioritized mitigations (CDN reroute, reduce bitrate, scale transcoders).
Verification: RUM & synthetic green for 10 consecutive minutes before de-escalation.
Post-incident: Publish postmortem within 72 hours with owners for each action item.

Example post-incident action items

Instrument additional RUM slices for ISP-level diagnostics (owner: Observability Team, due: 7 days).
Implement SLO burn-rate automation to trigger multi-region CDN failover (owner: Platform SRE, due: 14 days).
Pre-warm backup transcoder pool via scheduled warm jobs prior to event (owner: Media Ops, due: next event).

"A fast mitigation with a poor root cause analysis is temporary relief; a slow mitigation with a thorough postmortem perpetuates outages. Do both well."

Final notes — turning this playbook into operational muscle

Great playbooks are living documents. Treat this as a baseline: localize thresholds to your platform, rehearse regularly, and automate repetitive mitigations. In 2026, platforms that combine robust SLIs, AI-assisted detection, and practiced human processes will endure record simultaneous viewers and the unpredictable networks they use.

Call to action

Use this playbook as your starting template: copy the runbooks into your incident tooling, run a tabletop this week, and commit to a 72-hour postmortem cadence. Want a downloadable checklist or pre-filled Prometheus & runbook templates tailored to your stack? Contact your platform lead or visit manuals.top for ready-to-use operational bundles to deploy before your next big event.

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