APM Tips

Application performance monitoring

APM Tips

Instrument, query, alert. Field notes for production monitoring.

Practical guides for Azure Monitor Application Insights and OpenTelemetry, explained KQL, and calculators for sampling and cost. Every guide opens with the answer and dates its sources.

Start here

  • Hub

    Application Insights

    Configuration and troubleshooting for Azure Monitor Application Insights, for the classic SDK and the OpenTelemetry distros that replace it.

  • Library

    KQL library

    Explained, copy-paste queries for the Application Insights tables: latency percentiles, failures, slow dependencies, all sampling-aware.

  • Tools

    Tools

    A sampling and ingestion cost calculator and a KQL query builder, each showing how it arrives at its figures.

Latest guides

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Latest queries

KQL library →
  • Returns: One row per operation with its request count, the satisfied, tolerating and frustrated counts against the target, and a 0-to-1 score, worst first.

  • Availability results by test and location

    availabilityResults availability

    Returns: One row per availability test and test location with the number of runs, the failed runs, the availability percentage and the p95 test duration in milliseconds, worst first.

  • Availability test failures with their messages

    availabilityResults availability

    Returns: Up to 100 failed availability test runs from the last 24 hours, newest first, each with the test name, location, duration in milliseconds, failure message and operation_Id.