feat(AzureStorage): support orchestrator-only and activity-only worke…

[stevenhvtran]

Add a WorkerDispatchMode setting (Both/Orchestrator/Activity) so a worker can run only orchestrations+entities or only activities. Activity mode skips control-queue partition leasing; Orchestrator mode skips the work-item queue. TaskHubWorker starts only the enabled dispatchers via the existing dispatcher-count capabilities. Default Both preserves current behavior.

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[Copilot]

Pull request overview

Adds a decoupled “worker dispatch mode” capability for the Azure Storage backend so a worker can be configured to dispatch only orchestrations/entities, only activities, or both—enabling independent scaling of orchestration vs. activity workers on the same task hub.

Changes:

• Introduces WorkerDispatchMode and a corresponding AzureStorageOrchestrationServiceSettings.WorkerDispatchMode setting (default Both).
• Makes AzureStorageOrchestrationService disable dispatcher counts and skip control-queue partition leasing for activity-only workers, with additional “safety net” backoff in fetch loops.
• Updates TaskHubWorker to start only the dispatchers enabled by the backend’s dispatcher counts and adds a new Azurite-based decoupled worker test.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
Test/DurableTask.AzureStorage.Tests/DecoupledWorkerDispatchTests.cs	Adds unit + Azurite integration tests for orchestrator-only + activity-only cooperation on the same task hub.
src/DurableTask.Core/TaskHubWorker.cs	Gates dispatcher creation/start/stop based on dispatcher counts to support “disabled” dispatch types.
src/DurableTask.AzureStorage/WorkerDispatchMode.cs	Defines the new dispatch mode enum (Both/Orchestrator/Activity).
src/DurableTask.AzureStorage/AzureStorageOrchestrationServiceSettings.cs	Exposes WorkerDispatchMode setting with default Both.
src/DurableTask.AzureStorage/AzureStorageOrchestrationService.cs	Implements mode behavior via dispatcher counts, skips app lease manager in activity-only mode, and adds backoff safety nets.

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

Test/DurableTask.AzureStorage.Tests/DecoupledWorkerDispatchTests.cs:24

• This test file is under Test/ (capital T), but the repository’s solution references the Azure Storage test project under test/DurableTask.AzureStorage.Tests (lowercase). There is no Test/DurableTask.AzureStorage.Tests/*.csproj, so this test will not be compiled or executed in CI, meaning it won’t validate the new dispatch-mode behavior.

namespace DurableTask.AzureStorage.Tests
{
    using DurableTask.AzureStorage;
    using DurableTask.Core;
    using Microsoft.VisualStudio.TestTools.UnitTesting;
    using System;
    using System.Linq;
    using System.Threading.Tasks;

    [TestClass]
    public class DecoupledWorkerDispatchTests

src/DurableTask.Core/TaskHubWorker.cs:333

• TaskHubWorker now conditionally creates the orchestration/activity dispatchers based on dispatcher counts. This means TaskOrchestrationDispatcher / TaskActivityDispatcher can remain null even after StartAsync(), which is a behavioral change in the public API surface and can cause NullReferenceExceptions for consumers that configure dispatcher counts to 0 but still access these properties (e.g., to set IncludeDetails). Since WorkItemDispatcher already supports DispatcherCount = 0 (it simply starts zero loops), consider always constructing these dispatcher objects and only gating their StartAsync() calls.

                if (this.dispatchOrchestrations)
                {
                    this.orchestrationDispatcher = new TaskOrchestrationDispatcher(
                        this.orchestrationService,
                        this.orchestrationManager,
                        this.orchestrationDispatchPipeline,
                        this.logHelper,
                        this.ErrorPropagationMode,
                        this.versioningSettings,
                        this.ExceptionPropertiesProvider);
                }

                if (this.dispatchActivities)
                {
                    this.activityDispatcher = new TaskActivityDispatcher(
                        this.orchestrationService,
                        this.activityManager,
                        this.activityDispatchPipeline,
                        this.logHelper,
                        this.ErrorPropagationMode,
                        this.ExceptionPropertiesProvider);
                }

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.