Inventory detector coverage before the Application Insights smart-detection migration preview

Source facts

The Application Insights migration preview creates alert rules for supported smart detectors, but not every former capability survives. Microsoft’s mapping excludes, among others, slow page-load detection and potential-security-issue detection; excluded capabilities stop being supported for the migrated resource. Failure Anomalies already uses an alert rule and needs no migration. A detector disabled before migration remains disabled in its new rule. After migration, configuration uses smart-detection alert-rule templates rather than the Application Insights resource template. Microsoft Learn.

Applicability

This review concerns resources that still face the documented preview transition. Establish the actual current rule inventory and obtain any required preview approval. Do not assume that a similarly named rule represents the same retained capability.

DSE recommendation

Map every currently relied-on detector to a retained alert rule or an explicit replacement decision before migration. Ask the application owner to identify which removed detections matter to the service. Separate deliberate disabled states from accidental omissions, and have the automation owner update the configuration source used after transition. Avoid treating a successful migration operation as proof of unchanged monitoring coverage.

Verification

Compare the resulting rule inventory, enabled states and configuration authority with the approved mapping on a representative resource. Record unresolved replacement work separately from completed migration steps. Inspect the existing Failure Anomalies rule without counting it as a newly converted detector. Preserve the final mapping so later infrastructure deployments can be checked against the intended post-migration design.

Official references

Microsoft Learn: Smart-detection migration preview. Source reviewed September 9, 2026.