Monitoring

Monitor Pattern — Durable Task SDK (.NET)

.NET | Durable Task SDK

Description

Demonstrates the Monitor pattern using the Durable Task SDK. The orchestration periodically checks a simulated job status, sleeping between polls, until the job completes or a timeout is reached.

This pattern is useful for:

• Polling external APIs or services
• Waiting for long-running jobs to complete
• Implementing flexible timeouts with periodic checks

Prerequisites

1. .NET 8 SDK
2. Docker (for the emulator)

Quick Run

1. Start the Durable Task Scheduler emulator:

   docker run -d -p 8080:8080 -p 8082:8082 mcr.microsoft.com/dts/dts-emulator:latest

2. Start the worker (in one terminal):

   cd Worker
   dotnet run

3. Start the client (in another terminal):

   cd Client
   dotnet run

4. View orchestration progress in the dashboard: http://localhost:8082

How It Works

1. The orchestration starts monitoring a "job" with a unique ID
2. Each iteration calls the CheckJobStatus activity to poll the job state
3. If the job is complete, the orchestration returns the result
4. If not, it creates a durable timer to wait (e.g., 5 seconds) and then calls ContinueAsNew to restart with updated state
5. A timeout guard prevents infinite polling

Learn More

• Monitor Pattern
• Durable Task Scheduler Documentation