Observability, Data & Background Failures

Missing telemetry, lost correlation, Azure SQL timeouts, transient fault diagnosis, queue backlog, poison messages, and duplicate background processing.

7 drillsPractice one at a timeOrdered pathDebugging scenario

Recommended start

Missing Telemetry

Investigate a .NET API that appears to run but sends little or no telemetry to Application Insights.

Medium~10 minStep 1 of 7

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1Missing TelemetryRecommended startInvestigate a .NET API that appears to run but sends little or no telemetry to Application Insights.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 2Lost Queue CorrelationDiagnose missing trace continuity when an API enqueues work processed by an Azure worker.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 3SQL Timeouts After DeployInvestigate SQL timeouts that appear after a new .NET API release.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 4Transient vs Query RegressionDecide whether Azure SQL errors are transient platform faults or a real application/query regression.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 5Queue BacklogDiagnose a growing queue backlog in an Azure-based background processing system.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 6Poison and Dead-letterInvestigate messages that repeatedly fail and move to a poison queue or dead-letter queue.Debugging scenarioMedium~10 min.NETApplication InsightsASP.NET CorePractice 7Duplicate Background WorkTraces duplicate side effects across message delivery, lock ownership, settlement, durable job state, and external idempotency, then repairs affected users safely.Debugging scenarioHard~12 min.NETApplication InsightsASP.NET CorePractice