APM Tips

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• 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.

• Application Insights

  Correlation in Application Insights: trace context, operation_Id and Application Map

  How operation_Id and operation_ParentId map to W3C trace context, why Application Map shows one node or none, and how to correlate work across queues.

  Updated Oct 22, 2026 · 7 min read

• Application Insights

  Tracking users and sessions in API apps

  Why user_Id and session_Id are empty for APIs, how to set them from claims and headers in the classic SDK and OpenTelemetry, and what to keep out of them.

  Updated Oct 22, 2026 · 6 min read

• Application Insights

  Agent-based dependency tracking: what the Application Insights Agent sees and misses

  How the Application Insights Agent collects SQL and HTTP dependencies on IIS, when the instrumentation engine is needed, and what still needs code.

  Updated Oct 21, 2026 · 6 min read

• Application Insights

  App Service auto-instrumentation vs the SDK: which one to run

  What Application Insights auto-instrumentation collects on App Service, Functions, AKS and IIS, when to move to code, and why one collector per app is enough.

  Updated Oct 21, 2026 · 7 min read

• Application Insights

  Application Insights pricing: what you pay for, and how to cut the bill

  Application Insights bills by the GB its Log Analytics workspace ingests. Current East US prices, the free allowance and retention, and what to change first.

  Updated Oct 21, 2026 · 6 min read

• Application Insights

  ApplicationInsights.config: do you still need it, and what replaced it

  What ApplicationInsights.config controls, which apps still read it, and where its settings went in SDK 3.x and the Microsoft OpenTelemetry Distro.

  Updated Oct 21, 2026 · 6 min read

• Failed requests by result code

  requests failures

  Returns: One row per result code among failed requests, with the sampling-adjusted failure count, the number of distinct operations affected and one example operation.

  p50 p95 p99

• Apdex-style satisfaction score per operation

  requests latency

  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.

  p50 p95 p99

• 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.

  p50 p95 p99