Durable Functions orchestration patterns in Azure - Commands & Configuration

Introduction

Durable Functions help you run tasks that need to happen in order or repeat over time without losing track. They solve the problem of managing complex workflows in the cloud by keeping track of each step automatically.

When you want to run a series of tasks one after another and keep track of progress even if the system restarts.

When you need to run multiple tasks at the same time and wait for all to finish before moving on.

When you want to run a task repeatedly on a schedule or until a condition is met.

When you want to call a task many times with different inputs and collect all results.

When you want to handle errors and retries automatically in a long-running process.

Config File - function.json

function.json

{
  "bindings": [
    {
      "name": "context",
      "type": "orchestrationTrigger",
      "direction": "in"
    }
  ]
}

This file defines the function as an orchestration trigger, which means it starts and controls the workflow. The context is the object that manages the orchestration state and calls to other functions.

Commands

Starts the orchestration function named 'exampleOrchestrator' to begin the workflow.

Terminal

func durable start new --name exampleOrchestrator

Expected Output

Started orchestration with ID: 12345abcdef

Status: Running

→

--name - Specifies the name of the orchestration function to start

Checks the current status of the orchestration with the given ID to see progress or results.

Terminal

func durable status --id 12345abcdef

Expected Output

Orchestration ID: 12345abcdef

Status: Completed

Output: "Task results collected"

→

--id - Specifies the orchestration instance ID to query

Stops the orchestration with the given ID if you want to cancel the workflow before it finishes.

Terminal

func durable terminate --id 12345abcdef

Expected Output

Orchestration 12345abcdef terminated successfully.

→

--id - Specifies the orchestration instance ID to terminate

Key Concept

If you remember nothing else from this pattern, remember: Durable Functions keep track of each step in a workflow so your tasks run reliably and in order, even if the system restarts.

Common Mistakes

Starting an orchestration without specifying the correct function name

The orchestration will not start because the system cannot find the function to run.

Always use the exact orchestration function name with the --name flag when starting.

Not checking orchestration status after starting

You won't know if the workflow is running, completed, or failed, which can cause confusion.

Use the status command with the orchestration ID to monitor progress.

Terminating an orchestration without confirming the ID

You might stop the wrong workflow or fail to stop the intended one.

Always verify the orchestration ID before terminating.

Summary

Use the start command to begin a Durable Functions orchestration workflow.

Check the status command to monitor the progress and results of the orchestration.

Use the terminate command to stop an orchestration if needed.