Reliability: Synthetic Testing and Alerting
Overview
Proactively verifying availability and turning telemetry into actionable notifications — the detection half of continuous feedback that surfaces problems before (or as soon as) they impact users.
Units
- Validating application availability with synthetic tests
- Configuring Azure Monitor alert rules and action groups
- Severity, dynamic thresholds, and anomaly detection
- Responding to alerts and feeding findings back
Concepts introduced
- synthetic-testing — proactive, scripted availability checks from global locations.
- alerting — rule = signal + condition + action group.
- Application Insights — availability/availability tests (URL ping, standard, multi-step).
- Azure Monitor — alert rules and action groups based notifications.
Key terms & commands
- Availability tests in App Insights: URL ping (basic), standard (request + dependency), multi-step (recorded journey).
- An alert rule combines a signal (metric/log/availability) with a condition, and fires an action group (email, SMS, webhook/ITSM).
- Tests run from multiple global locations on a schedule.
Hands-on
- Create an App Insights availability (URL ping) test and an alert on failure.
- Define an alert rule + action group for a metric threshold.
Exam focus
- Synthetic = proactive availability (“is it up?”), telemetry = reactive/real-user.
- Know the alert anatomy: rule → signal + condition → action group.
- Availability-test failure is a common alert source.
Related
synthetic-testing · alerting · application-insights · azure-monitor · Path MOC