Dependency Failure BlobContainerClient.CreateIfNotExists

Error message (sample)

App Insights may record dependency failures with HTTP 409 when a blob container or blob already exists.

Symptoms

• App Insights shows 409 dependency failures related to BlobContainerClient.CreateIfNotExists.

Scope

This can occur on both SaaS Model and Customer Hosted Model installations.

Known instances

Polling Engine

Root cause

ProcessFactorial uses Azure Blob to control leases and ensure certain processes are only running once across scaled instances. The platform ensures required blobs exist; concurrent attempts or restarts can lead to CreateIfNotExists returning a 409 when the blob is already present.

Resolution

This behaviour is expected and harmless; the operation is retried or ignored by the platform. See General App Insights Guidelines for guidance on telemetry noise.

Verification checklist

• [ ] Failures are benign (followed by no operational impact)
• [ ] Telemetry noise is acceptable or suppressed intentionally