Q: What is an absence alert, and when would you use one?
An absence alert fires when expected telemetry stops arriving.
#Observability #Procedure #1: Clear Deadlock #L1 #Monitoring #Prometheus #SRE
🎙️ Candidate Opening & Architectural Context
""Logs tell you what happened, metrics tell you where to look, and distributed traces pinpoint the exact slow component. The interviewer is testing: Missing signal detection.. I structure my answer around systematic triage first, root cause analysis second, and permanent remediation third.""
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🛠️ Production Runbook & Step-by-Step Resolution
1️⃣
Initial Diagnostics & Root Cause Analysis
An absence alert fires when expected telemetry stops arriving.
- A cron job should publish
backup_success_totalevery night, but no sample appears. - A payment service should always have some traffic during business hours, but request metrics disappear.
- A log shipper stops sending heartbeat logs.
2️⃣
Remediation & Permanent Safeguards
Examples: This is different from alerting on a metric value. You are alerting that the signal itself is missing. Absence alerts are useful for batch jobs, telemetry pipelines, and critical services where "no data" might mean monitoring is broken or the job never ran.
💡 The Senior SRE Gold Nugget (Key Architectural Takeaway)
"Pro-Tip: A cron job should publish backup_success_total every night, but no sample appears.."
⚡ 60-Second Elevator Pitch Talking Points
- A cron job should publish backup_success_total every night, but no sample appears.
- A payment service should always have some traffic during business hours, but request metrics disa...
- A log shipper stops sending heartbeat logs.
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