hello-orchestrations

Hello Orchestrations

Demonstrates four fundamental orchestration patterns every Durable Task developer needs.

Features Covered

Feature	API
Activity sequence	ctx.callActivity() in a loop
Fan-out/fan-in	whenAll() with parallel callActivity()
Sub-orchestrations	ctx.callSubOrchestrator()
Race pattern	whenAny()

Prerequisites

• Node.js ≥ 22
• Docker (for the DTS Emulator)

Setup

# From the repository root
cd examples/azure-managed
docker compose up -d          # start DTS emulator
cp .env.emulator .env         # configure for local emulator
cd ../..
npm install && npm run build

Run

npm run example -- ./examples/azure-managed/hello-orchestrations/index.ts

Expected Output

=== 1. Activity Sequence ===
Result: [1,2,3,4,5,6]

=== 2. Fan-out/Fan-in ===
Result: {"items":4,"totalChars":24}

=== 3. Sub-orchestrations ===
Result: {"result1":12,"result2":22}

=== 4. whenAny (Race) ===
Result: {"winnerResult":5}

=== All orchestrations completed successfully! ===

Smoke Test

npm run example -- ./examples/azure-managed/hello-orchestrations/index.ts 2>&1 | grep "All orchestrations completed successfully"

Troubleshooting

• Connection refused: Ensure the DTS emulator is running (docker compose up -d from the examples/azure-managed directory).
• Worker timeout: The emulator may need a few seconds to start. Retry the command.

Running Against Azure Managed DTS (Cloud)

To run this sample against a real Azure Managed Durable Task Scheduler instead of the local emulator:

1. Create a scheduler and task hub (if you haven't already) — see the parent README for az durabletask commands.

2. Configure .env for your cloud endpoint:

   cd examples/azure-managed
   cp .env.example .env
   # Edit .env with your scheduler endpoint and task hub name

   Example .env:

   DURABLE_TASK_SCHEDULER_CONNECTION_STRING=Endpoint=https://your-scheduler.eastus.durabletask.io;Authentication=DefaultAzure;TaskHub=your-taskhub

3. Authenticate with Azure:

   az login

4. Run (no Docker needed):

   npm run example -- ./examples/azure-managed/hello-orchestrations/index.ts