Add thread-safe status tracking to pipeline steps #12312

Copilot · 2025-10-23T15:37:56Z

Summary

This PR implements thread-safe status tracking for pipeline steps, allowing the pipeline execution engine to track whether steps are pending, running, succeeded, failed, canceled, or skipped. This provides better visibility into pipeline execution state and enables improved error reporting and diagnostics.

Changes

New `PipelineStepStatus` Enum

Added a new enum with six status values representing the lifecycle of a pipeline step:

public enum PipelineStepStatus
{
    Pending,    // Step is waiting to start
    Running,    // Step is currently executing
    Succeeded,  // Step completed successfully
    Failed,     // Step failed during execution
    Canceled,   // Step was canceled before completion
    Skipped     // Step was skipped and not executed
}

Updated `PipelineStep` Class

Modified the PipelineStep class to support thread-safe status management:

Changed Status to a read-only property backed by a private field with lock-based synchronization
Added internal TryTransitionStatus() method for validated, thread-safe state transitions
Implemented state transition validation to prevent invalid transitions:
- Pending → Running, Failed (dependency failure), or Skipped (filtered out)
- Running → Succeeded, Failed, or Canceled
- Terminal states (Succeeded, Failed, Canceled, Skipped) cannot transition to other states
- Same-state transitions are idempotent

public PipelineStepStatus Status { get; } // Read-only, thread-safe
internal bool TryTransitionStatus(PipelineStepStatus newStatus) // Validated transitions

Automatic Status Management

Modified the DistributedApplicationPipeline execution engine to automatically update step status throughout the execution lifecycle using the thread-safe transition method:

Pending → Running: Status is set when step execution begins
Running → Succeeded: Status is set when step completes successfully
Running → Failed: Status is set when step throws an exception
Running → Canceled: Status is set when step is canceled via OperationCanceledException
Pending → Failed: Dependent steps are marked as failed when their dependencies fail
Pending → Skipped: Steps that are filtered out (not in the execution path) are marked as skipped

The implementation ensures that OperationCanceledException is properly preserved (not wrapped) to enable correct cancellation detection, and eliminates duplicate status assignments in exception handling paths.

Testing

Added comprehensive test coverage with 12 new tests covering:

Default status initialization
Successful execution status transitions
Failed execution status transitions
Canceled execution status transitions
Multiple independent steps tracking status
Dependent steps with proper status transitions
Failed dependencies marking dependent steps as failed
Invalid state transition validation
Valid state transition validation
Same-state transition handling
Filtered steps being marked as skipped
Skipped status transition validation

All 76 pipeline tests pass (64 existing + 12 new) with no regressions.

Benefits

📊 Track execution progress of individual pipeline steps
🔍 Identify which steps succeeded, failed, were canceled, or were skipped at a glance
🎯 Monitor overall pipeline execution state
🐛 Enable better error reporting and diagnostics
🖥️ Support status-based UI updates for deployment dashboards
🔒 Thread-safe status management prevents race conditions
✅ State validation ensures status integrity
⏭️ Clear indication of skipped steps in filtered executions

Breaking Changes

None. This is a purely additive feature. The status property remains publicly readable, and the internal transition method is only used by the pipeline execution engine. The status property is automatically managed by the pipeline execution engine and requires no changes from consumers.

Fixes #12282

Original prompt

This section details on the original issue you should resolve

<issue_title>Support modeling status on pipeline steps</issue_title>
<issue_description>Pipeline steps don't currently support modeling their status. We should add this so we can track if steps are waiting, running, or completed. The status should also capture completion state.

Introduce a new PipelineStepStatus enum.
enum PipelineStepStatus {
    Pending,
    Running,
    Succeeded,
    Failed,
    Canceled
}
Add a Status property to a PipelineStep

Update the DistributedApplicationPipeline to set the status on each of those steps</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #12282

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

Co-authored-by: captainsafia <1857993+captainsafia@users.noreply.github.com>

github-actions · 2025-10-23T18:02:03Z

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 12312

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 12312"

src/Aspire.Hosting/Pipelines/PipelineStep.cs

Copilot

Pull Request Overview

This PR adds status tracking capabilities to pipeline steps, enabling the pipeline execution engine to monitor the lifecycle state of each step through five distinct statuses: Pending, Running, Succeeded, Failed, and Canceled. This enhances visibility into pipeline execution and supports better diagnostics.

Key Changes:

Introduced PipelineStepStatus enum with five lifecycle states
Added automatic status management in DistributedApplicationPipeline that updates step status throughout execution
Included comprehensive test coverage with 7 new tests validating all status transitions

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/Aspire.Hosting/Pipelines/PipelineStepStatus.cs	New enum defining the five possible execution states for pipeline steps
src/Aspire.Hosting/Pipelines/PipelineStep.cs	Added Status property with default value of Pending
src/Aspire.Hosting/Pipelines/DistributedApplicationPipeline.cs	Implemented automatic status tracking logic throughout step execution lifecycle
tests/Aspire.Hosting.Tests/Pipelines/DistributedApplicationPipelineTests.cs	Added 7 new tests covering all status transition scenarios

Copilot · 2025-10-23T18:28:29Z

src/Aspire.Hosting/Pipelines/DistributedApplicationPipeline.cs

+                catch (OperationCanceledException)
+                {
+                    // Cancellation - mark as canceled and re-throw
+                    step.Status = PipelineStepStatus.Canceled;


Duplicate status assignment for Canceled state. The status is already set to Canceled in the inner catch block (lines 386-390). This outer catch will only execute if the inner try-catch is bypassed, but the inner catch already handles OperationCanceledException and re-throws it. Consider removing this outer catch block to eliminate the redundancy.

Suggested change

step.Status = PipelineStepStatus.Canceled;

Fixed in commit 526ca72. Removed the duplicate outer catch block for OperationCanceledException - status is now only set once in the inner catch block.

Copilot · 2025-10-23T18:28:30Z

src/Aspire.Hosting/Pipelines/DistributedApplicationPipeline.cs

                catch (Exception ex)
                {
                    // Execution failure - mark as failed, cancel all other work, and re-throw
+                    step.Status = PipelineStepStatus.Failed;


Duplicate status assignment for Failed state. The status is already set to Failed in the inner catch block (line 393). This outer catch will receive the re-thrown exception from the inner catch, causing the Failed status to be set twice. The outer assignment on line 416 is redundant.

Suggested change

step.Status = PipelineStepStatus.Failed;

Fixed in commit 526ca72. Removed the duplicate outer catch block for Failed status - status is now only set once in the inner catch block.

Copilot · 2025-10-23T18:28:30Z

tests/Aspire.Hosting.Tests/Pipelines/DistributedApplicationPipelineTests.cs

+        using var builder = TestDistributedApplicationBuilder.Create(DistributedApplicationOperation.Publish, publisher: "default", isDeploy: true);
+        var pipeline = new DistributedApplicationPipeline();
+
+        var statusTransitions = new Dictionary<string, List<PipelineStepStatus>>();


The variable 'statusTransitions' is declared but never used in this test. Consider removing this unused variable declaration.

Suggested change

var statusTransitions = new Dictionary<string, List<PipelineStepStatus>>();

Fixed in commit 526ca72. Removed the unused statusTransitions variable declaration.

eerhardt · 2025-10-23T18:35:07Z

src/Aspire.Hosting/Pipelines/DistributedApplicationPipeline.cs


                        // Wrap the dependency failure with context about this step
                        var wrappedException = new InvalidOperationException(message, ex);
+                        step.Status = PipelineStepStatus.Failed;


Do we need to worry about concurrency at all? Is it possible for 2 threads to try to update the status at the same time?

Yes, all state changes need to be guarded and thread safe. We need to make sure that transitions are valid (you can't flip between arbitrary states).

Fixed in commit 526ca72. Made status changes thread-safe by:

Changed Status to a read-only property backed by a private field

Added TryTransitionStatus() internal method that uses a lock for thread-safe updates

Implemented state transition validation to ensure only valid transitions are allowed (e.g., Pending→Running, Running→Succeeded/Failed/Canceled, but no transitions from terminal states)

Added 3 new tests to validate the state transition logic

davidfowl · 2025-10-23T20:23:37Z

@copilot implement the review feedback. Make the state change a method instead of a property and guard against invalid state transitions.

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot · 2025-10-23T20:31:54Z

@copilot implement the review feedback. Make the state change a method instead of a property and guard against invalid state transitions.

Implemented in commit 526ca72. Changes made:

Changed to method-based approach: Replaced the Status property setter with an internal TryTransitionStatus() method
Thread-safe implementation: Used lock mechanism to ensure thread-safe status updates
State transition validation: Added IsValidTransition() method that enforces valid state transitions:
- Pending can transition to Running or Failed (dependency failure)
- Running can transition to Succeeded, Failed, or Canceled
- Terminal states (Succeeded, Failed, Canceled) cannot transition to other states
- Same-state transitions are allowed (idempotent)
Updated pipeline execution: All status assignments now use TryTransitionStatus()
Removed duplicate assignments: Fixed the duplicate status assignments in outer catch blocks
Added tests: 3 new tests validate state transition logic

All 74 tests pass.

davidfowl · 2025-10-23T20:35:19Z

@copilot We should be setting the state to Canceled for OperationCancelledException. We should add a Skipped status if a task was not run.

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot · 2025-10-23T20:42:14Z

@copilot We should be setting the state to Canceled for OperationCancelledException. We should add a Skipped status if a task was not run.

Implemented in commit 966cece. Changes made:

Added Skipped status: Added a new PipelineStepStatus.Skipped enum value for steps that are not executed
Status already set to Canceled: Confirmed OperationCanceledException correctly sets status to Canceled (lines 386-390 in DistributedApplicationPipeline.cs)
Mark filtered steps as Skipped: Updated FilterStepsForExecution to mark steps that are filtered out (not in the execution path) as Skipped
State transition validation: Updated IsValidTransition to allow Pending → Skipped transitions
Added tests: 2 new tests validate the Skipped status behavior

All 76 tests pass.

Initial plan

d21816b

Copilot AI assigned Copilot and captainsafia Oct 23, 2025

Copilot started work on behalf of captainsafia October 23, 2025 15:38 View session

Add pipeline step status tracking with enum and tests

64da23b

Co-authored-by: captainsafia <1857993+captainsafia@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Support modeling status on pipeline steps~~ Add status tracking to pipeline steps Oct 23, 2025

Copilot AI requested a review from captainsafia October 23, 2025 15:55

Copilot finished work on behalf of captainsafia October 23, 2025 15:55

Merge branch 'main' into copilot/add-pipeline-step-status

f29f346

captainsafia reviewed Oct 23, 2025

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captainsafia marked this pull request as ready for review October 23, 2025 18:27

captainsafia requested a review from mitchdenny as a code owner October 23, 2025 18:27

Copilot AI review requested due to automatic review settings October 23, 2025 18:27

Copilot AI reviewed Oct 23, 2025

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captainsafia requested review from Erarndt, davidfowl and eerhardt and removed request for Erarndt October 23, 2025 18:30

eerhardt reviewed Oct 23, 2025

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eerhardt approved these changes Oct 23, 2025

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Copilot started work on behalf of davidfowl October 23, 2025 20:24 View session

Make status transitions thread-safe with validation

526ca72

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot AI changed the title ~~Add status tracking to pipeline steps~~ Add thread-safe status tracking to pipeline steps Oct 23, 2025

Copilot finished work on behalf of davidfowl October 23, 2025 20:33

Copilot started work on behalf of davidfowl October 23, 2025 20:35 View session

Add Skipped status for steps that are not executed

966cece

Co-authored-by: davidfowl <95136+davidfowl@users.noreply.github.com>

Copilot finished work on behalf of davidfowl October 23, 2025 20:43

Add thread-safe status tracking to pipeline steps #12312

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Add thread-safe status tracking to pipeline steps #12312

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Summary

Changes

New PipelineStepStatus Enum

Updated PipelineStep Class

Automatic Status Management

Testing

Benefits

Breaking Changes

Comments on the Issue (you are @copilot in this section)

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Copilot AI commented Oct 23, 2025 •

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New `PipelineStepStatus` Enum

Updated `PipelineStep` Class

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