Add the ability to start and stop IHostedService instances concurrently #75894

jerryk414 · 2022-09-20T14:26:39Z

Implements #68036

…ged mid-execution; add support for stop behavior and exception behavior to be set in config file

…onously

…called "concurrently" or sequentially

dotnet-issue-labeler · 2022-09-20T14:26:48Z

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, to please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

ghost · 2022-09-20T14:26:54Z

Tagging subscribers to this area: @dotnet/area-extensions-hosting
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Issue Details

Implements #68036

Author:	jerryk414
Assignees:	-
Labels:	`new-api-needs-documentation`, `area-Extensions-Hosting`
Milestone:	-

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

jerryk414 · 2022-09-21T16:52:22Z

I'm not sure why the check runtime (Libraries Test Run release coreclr Linux_musl x64 Debug) is failing - i've checked the logs and everything i'm seeing indicates that the actual tests are succeeding but some portion of the process to run the tests is failing.

It looks like it's failing on the Send to Helix step. I did find a helix log that indicates that the issue is unrelated to my changes but related to an issue with uploading helix logs.

Seems like this could be related to #74699.

Any assistance would be appreciated.

eerhardt

Thanks for the contribution, @jerryk414!

eerhardt · 2022-09-29T02:02:06Z

src/libraries/Microsoft.Extensions.Hosting/src/HostOptions.cs

@@ -17,6 +17,16 @@ public class HostOptions
        /// </summary>
        public TimeSpan ShutdownTimeout { get; set; } = TimeSpan.FromSeconds(30);

+        /// <summary>
+        /// Determines if the <see cref="IHost"/> will start registered instances of <see cref="IHostedService"/> concurrently or sequentially


It would be good to document the default.

eerhardt · 2022-09-29T02:02:49Z

src/libraries/Microsoft.Extensions.Hosting/src/HostOptions.cs

@@ -30,11 +40,25 @@ public class HostOptions
        internal void Initialize(IConfiguration configuration)
        {
            var timeoutSeconds = configuration["shutdownTimeoutSeconds"];
-            if (!string.IsNullOrEmpty(timeoutSeconds)
+            if (!string.IsNullOrWhiteSpace(timeoutSeconds)


This change seems unrelated/unnecessary.

I don't understand why you would want to use NullOrEmpty over NullOrWhiteSpace here. The TryParse methods further down the chain will handle the blank-space scenarios, but I don't see a need to even get there when we can stop it so easily.

The odds that the config value is going to be just whitespace are VERY low. So doing extra checking just slows down the happy path.

Look at the implementation of IsNullOrWhiteSpace:

runtime/src/libraries/System.Private.CoreLib/src/System/String.cs

Lines 491 to 501 in f518c05

public static bool IsNullOrWhiteSpace([NotNullWhen(false)] string? value)

{

if (value == null) return true;

for (int i = 0; i < value.Length; i++)

{

if (!char.IsWhiteSpace(value[i])) return false;

}

return true;

}

It goes through the string checking the chars one by one. There is no reason to do this.

eerhardt · 2022-09-29T13:19:45Z

src/libraries/Microsoft.Extensions.Hosting/src/HostOptions.cs

                && int.TryParse(timeoutSeconds, NumberStyles.None, CultureInfo.InvariantCulture, out var seconds))
            {
                ShutdownTimeout = TimeSpan.FromSeconds(seconds);
            }
+
+            var servicesStartConcurrently = configuration["servicesStartConcurrently"];
+            if (!string.IsNullOrWhiteSpace(servicesStartConcurrently)


Suggested change

if (!string.IsNullOrWhiteSpace(servicesStartConcurrently)

if (!string.IsNullOrEmpty(servicesStartConcurrently)

eerhardt · 2022-09-29T13:20:06Z

src/libraries/Microsoft.Extensions.Hosting/src/HostOptions.cs

+            }
+
+            var servicesStopConcurrently = configuration["servicesStopConcurrently"];
+            if (!string.IsNullOrWhiteSpace(servicesStopConcurrently)


Suggested change

if (!string.IsNullOrWhiteSpace(servicesStopConcurrently)

if (!string.IsNullOrEmpty(servicesStopConcurrently)

eerhardt · 2022-09-29T13:24:15Z

src/libraries/Microsoft.Extensions.Hosting/tests/UnitTests/HostTests.cs

+                foreach (bool stopConcurrently in new[] { true, false })
+                    foreach (bool startConcurrently in new[] { true, false })
+                        foreach (int hostedServiceCount in new[] { 0, 1, 10 })
+                        {
+                            yield return new object[] { stopConcurrently, startConcurrently, hostedServiceCount };
+                        }


Suggested change

foreach (bool stopConcurrently in new[] { true, false })

foreach (bool startConcurrently in new[] { true, false })

foreach (int hostedServiceCount in new[] { 0, 1, 10 })

{

yield return new object[] { stopConcurrently, startConcurrently, hostedServiceCount };

}

foreach (bool stopConcurrently in new[] { true, false })

{

foreach (bool startConcurrently in new[] { true, false })

{

foreach (int hostedServiceCount in new[] { 0, 1, 10 })

{

yield return new object[] { stopConcurrently, startConcurrently, hostedServiceCount };

}

}

}

See rules 1 and 18 in https://github.com/dotnet/runtime/blob/main/docs/coding-guidelines/coding-style.md

eerhardt · 2022-09-29T13:47:05Z

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

                {
-                    foreach (IHostedService hostedService in _hostedServices.Reverse())
+                    // Ensure hosted services are stopped in FILO order


Suggested change

// Ensure hosted services are stopped in FILO order

// Ensure hosted services are stopped in LIFO order

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

eerhardt · 2022-09-29T13:57:33Z

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

+                        _logger.HostedServiceStartupFaulted(exceptions[0]);
+                        ExceptionDispatchInfo.Capture(exceptions[0]).Throw();
+                    }
+                    else
+                    {
+                        var ex = new AggregateException("One or more hosted services failed to stop.", exceptions);
+                        _logger.HostedServiceStartupFaulted(ex);


This is stopping, not starting

Suggested change

_logger.HostedServiceStartupFaulted(exceptions[0]);

ExceptionDispatchInfo.Capture(exceptions[0]).Throw();

}

else

{

var ex = new AggregateException("One or more hosted services failed to stop.", exceptions);

_logger.HostedServiceStartupFaulted(ex);

_logger.StoppedWithException(exceptions[0]);

ExceptionDispatchInfo.Capture(exceptions[0]).Throw();

}

else

{

var ex = new AggregateException("One or more hosted services failed to stop.", exceptions);

_logger.StoppedWithException(ex);

Oof good catch, i don't know how I missed that

eerhardt · 2022-09-29T14:00:03Z

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

+                }
+                catch (Exception ex)
+                {
+                    exceptions.AddRange(tasks.Exception?.InnerExceptions?.ToArray() ?? new[] { ex });


Suggested change

exceptions.AddRange(tasks.Exception?.InnerExceptions?.ToArray() ?? new[] { ex });

exceptions.AddRange(tasks.Exception?.InnerExceptions ?? new[] { ex });

There's no need to ToArray() here. Same comment for the stopping code.

eerhardt · 2022-09-29T14:04:49Z

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs

-                IList<Exception> exceptions = new List<Exception>();
-                if (_hostedServices != null) // Started?
+                List<Exception> exceptions = new List<Exception>();
+                if (_hostedServices?.Any() == true) // Started?


Why the change to call Any() here?

I suppose the inner block here might succeed even if the list is empty. I'm not 100% sure what happens if you pass an empty list of tasks into Task.WhenAll, so i'll have to figure that out.

I just felt like it wasn't necessary to even have to worry about that.

maryamariyan · 2022-10-11T19:31:48Z

Thanks for the contribution @jerryk414 let me know if you have any blockers with addressing the remaining feedback.

ghost · 2022-10-26T03:02:03Z

This pull request has been automatically marked no-recent-activity because it has not had any activity for 14 days. It will be closed if no further activity occurs within 14 more days. Any new comment (by anyone, not necessarily the author) will remove no-recent-activity.

tarekgh · 2022-11-01T21:18:54Z

Closing it we can consider opening when we get more feedback.

jerryk414 and others added 6 commits April 19, 2022 10:42

Stop IHostedService instances asynchronously by default

f17c035

Add missing refs; add unit tests; ensure stop behavior cannot be chan…

3798699

…ged mid-execution; add support for stop behavior and exception behavior to be set in config file

Merge branch 'main' into Stop-IHostedService-instances-asynchronously

8d804b4

Merge branch 'dotnet:main' into Stop-IHostedService-instances-asynchr…

99986e7

…onously

Merge branch 'dotnet:main' into Stop-IHostedService-instances-asynchr…

e0257b8

…onously

Use booleans to determine if both StartAsync and StopAsync should be …

ff29ba5

…called "concurrently" or sequentially

dotnet-issue-labeler bot added area-Extensions-Hosting new-api-needs-documentation labels Sep 20, 2022

ghost added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2022

jkrmo added 4 commits September 20, 2022 10:35

Add a custom logger message for startup failures

92be997

Fix LogLevel check

335c576

Semantics

fd8a0c7

If a single error is thrown, do not wrap it in an aggregate exception.

e634a6c

jerryk414 commented Sep 20, 2022

View reviewed changes

src/libraries/Microsoft.Extensions.Hosting/src/Internal/Host.cs Show resolved Hide resolved

tarekgh added this to the 8.0.0 milestone Sep 20, 2022

Fix tests; short-circuit StartAsync on first sequential failure

946a3d4

eerhardt reviewed Sep 29, 2022

View reviewed changes

Nick-Stanton added the needs-author-action An issue or pull request that requires more info or actions from the author. label Oct 11, 2022

maryamariyan mentioned this pull request Oct 24, 2022

Microsoft.Extensions work planned for .NET 8 #77390

Closed

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ghost added the no-recent-activity label Oct 26, 2022

tarekgh closed this Nov 1, 2022

ghost locked as resolved and limited conversation to collaborators Dec 2, 2022

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Add the ability to start and stop IHostedService instances concurrently #75894

Add the ability to start and stop IHostedService instances concurrently #75894

jerryk414 commented Sep 20, 2022

dotnet-issue-labeler bot commented Sep 20, 2022

ghost commented Sep 20, 2022

jerryk414 commented Sep 21, 2022 •

edited

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eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

jerryk414 Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

jerryk414 Sep 29, 2022

eerhardt Sep 29, 2022

eerhardt Sep 29, 2022

jerryk414 Sep 29, 2022

maryamariyan commented Oct 11, 2022

ghost commented Oct 26, 2022

tarekgh commented Nov 1, 2022

	public static bool IsNullOrWhiteSpace([NotNullWhen(false)] string? value)
	{
	if (value == null) return true;

	for (int i = 0; i < value.Length; i++)
	{
	if (!char.IsWhiteSpace(value[i])) return false;
	}

	return true;
	}

	if (!string.IsNullOrWhiteSpace(servicesStartConcurrently)
	if (!string.IsNullOrEmpty(servicesStartConcurrently)

	if (!string.IsNullOrWhiteSpace(servicesStopConcurrently)
	if (!string.IsNullOrEmpty(servicesStopConcurrently)

	// Ensure hosted services are stopped in FILO order
	// Ensure hosted services are stopped in LIFO order

	exceptions.AddRange(tasks.Exception?.InnerExceptions?.ToArray() ?? new[] { ex });
	exceptions.AddRange(tasks.Exception?.InnerExceptions ?? new[] { ex });

Add the ability to start and stop IHostedService instances concurrently #75894

Add the ability to start and stop IHostedService instances concurrently #75894

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jerryk414 commented Sep 20, 2022

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ghost commented Sep 20, 2022

jerryk414 commented Sep 21, 2022 • edited Loading

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maryamariyan commented Oct 11, 2022

ghost commented Oct 26, 2022

tarekgh commented Nov 1, 2022

jerryk414 commented Sep 21, 2022 •

edited

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