Propagate cancellation tokens through monitoring hosting and background services

src/ServiceControl.Monitoring.AcceptanceTests/.editorconfig

@@ -2,9 +2,3 @@
 
 # Justification: Test project
 dotnet_diagnostic.CA2007.severity = none
-
-# Cancellation analyzer debt. These fire because Particular.Analyzers is no longer pinned to 0.9.0.
-# They are scheduled work, not accepted exceptions: remove a line once this project has no
-# violations of that rule left, and never add a rule back to this list.
-dotnet_diagnostic.PS0003.severity = none
-dotnet_diagnostic.PS0018.severity = none

src/ServiceControl.Monitoring.AcceptanceTests/PerformanceTests.cs

@@ -64,9 +64,9 @@ public async Task GetMonitoredEndpointsQueryTest(int numberOfEndpoints, int numb
             var reporters =
                 new[]
                 {
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => criticalTimeStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName))),
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => processingTimeStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName))),
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => retriesStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName)))
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => criticalTimeStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName)), source.Token),
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => processingTimeStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName)), source.Token),
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => retriesStore.Store(e, i, EndpointMessageType.Unknown(i.EndpointName)), source.Token)
                 }.SelectMany(i => i).ToArray();
 
             var histogram = CreateTimeHistogram();
@@ -123,9 +123,9 @@ public async Task GetMonitoredSingleEndpointQueryTest(int numberOfInstances, int
             var reporters =
                 new[]
                 {
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => criticalTimeStore.Store(e, i, getter())),
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => processingTimeStore.Store(e, i, getter())),
-                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, source, (e, i) => retriesStore.Store(e, i, getter()))
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => criticalTimeStore.Store(e, i, getter()), source.Token),
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => processingTimeStore.Store(e, i, getter()), source.Token),
+                    BuildReporters(sendReportEvery, numberOfEntriesInReport, instances, (e, i) => retriesStore.Store(e, i, getter()), source.Token)
                 }.SelectMany(i => i).ToArray();
 
             var histogram = CreateTimeHistogram();
@@ -149,21 +149,21 @@ public async Task GetMonitoredSingleEndpointQueryTest(int numberOfInstances, int
             Report("Reporters", reportFinalHistogram, TimeSpan.FromMilliseconds(20));
         }
 
-        static IEnumerable<Task<LongHistogram>> BuildReporters(int sendReportEvery, int numberOfEntriesInReport, EndpointInstanceId[] instances, CancellationTokenSource source, Action<RawMessage.Entry[], EndpointInstanceId> store)
+        static IEnumerable<Task<LongHistogram>> BuildReporters(int sendReportEvery, int numberOfEntriesInReport, EndpointInstanceId[] instances, Action<RawMessage.Entry[], EndpointInstanceId> store, CancellationToken cancellationToken)
         {
             return instances
-                .Select(instance => StartReporter(sendReportEvery, numberOfEntriesInReport, source, instance, store))
+                .Select(instance => StartReporter(sendReportEvery, numberOfEntriesInReport, instance, store, cancellationToken))
                 .ToArray();
         }
 
-        static Task<LongHistogram> StartReporter(int sendReportEvery, int numberOfEntriesInReport, CancellationTokenSource source, EndpointInstanceId instance, Action<RawMessage.Entry[], EndpointInstanceId> store)
+        static Task<LongHistogram> StartReporter(int sendReportEvery, int numberOfEntriesInReport, EndpointInstanceId instance, Action<RawMessage.Entry[], EndpointInstanceId> store, CancellationToken cancellationToken)
         {
             return Task.Run(async () =>
             {
                 var entries = new RawMessage.Entry[numberOfEntriesInReport];
                 var histogram = CreateTimeHistogram();
 
-                while (source.IsCancellationRequested == false)
+                while (cancellationToken.IsCancellationRequested == false)
                 {
                     var now = DateTime.UtcNow;
 
@@ -178,7 +178,9 @@ static Task<LongHistogram> StartReporter(int sendReportEvery, int numberOfEntrie
                     var elapsed = Stopwatch.GetTimestamp() - start;
                     histogram.RecordValue(elapsed);
 
-                    await Task.Delay(sendReportEvery);
+                    // Not cancelled: the loop exits on the next check and the task has to complete
+                    // normally, because MergeHistograms reads the histogram it returns.
+                    await Task.Delay(sendReportEvery, CancellationToken.None);
                 }
 
                 return histogram;
@@ -247,8 +249,8 @@ public void TrackEndpointInputQueue(EndpointToQueueMapping queueToTrack)
         {
         }
 
-        public Task StartAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+        public Task StartAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;
 
-        public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+        public Task StopAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;
     }
 }

src/ServiceControl.Monitoring.AcceptanceTests/TestSupport/ServiceControlComponentBehavior.cs

@@ -21,7 +21,9 @@ public ServiceControlComponentBehavior(ITransportIntegration transportToUse, Act
         public HttpClient HttpClient => runner.HttpClient;
         public JsonSerializerOptions SerializerOptions => runner.SerializerOptions;
 
+#pragma warning disable PS0018 // IComponentBehavior declares this without a CancellationToken
         public async Task<ComponentRunner> CreateRunner(RunDescriptor run)
+#pragma warning restore PS0018
         {
             runner = new ServiceControlComponentRunner(transportIntegration, setSettings, customConfiguration);
             await runner.Initialize(run);

src/ServiceControl.Monitoring.AcceptanceTests/TestSupport/ServiceControlComponentRunner.cs

@@ -34,9 +34,9 @@ class ServiceControlComponentRunner(
         public HttpClient HttpClient { get; private set; }
         public JsonSerializerOptions SerializerOptions => Infrastructure.SerializerOptions.Default;
 
-        public Task Initialize(RunDescriptor run) => InitializeServiceControl(run.ScenarioContext);
+        public Task Initialize(RunDescriptor run, CancellationToken cancellationToken = default) => InitializeServiceControl(run.ScenarioContext, cancellationToken);
 
-        async Task InitializeServiceControl(ScenarioContext context)
+        async Task InitializeServiceControl(ScenarioContext context, CancellationToken cancellationToken)
         {
             LoggerUtil.ActiveLoggers = Loggers.Test;
             settings = new Settings(transportType: transportToUse.TypeName)
@@ -79,7 +79,7 @@ async Task InitializeServiceControl(ScenarioContext context)
             using (new DiagnosticTimer($"Creating infrastructure for {settings.InstanceName}"))
             {
                 var setupCommand = new SetupCommand();
-                await setupCommand.Execute(new HostArguments([]), settings);
+                await setupCommand.Execute(new HostArguments([]), settings, cancellationToken);
             }
 
             var configuration = new EndpointConfiguration(settings.InstanceName);
@@ -127,7 +127,7 @@ async Task InitializeServiceControl(ScenarioContext context)
                 host.UseTestRemoteIp();
                 host.UseServiceControlAuthentication(settings.OpenIdConnectSettings.Enabled);
                 host.UseServiceControlMonitoring(settings.ForwardedHeadersSettings, settings.HttpsSettings, settings.CorsSettings);
-                await host.StartAsync();
+                await host.StartAsync(cancellationToken);
 
                 HttpClient = host.Services.GetRequiredKeyedService<TestServer>(settings.InstanceName).CreateClient();
             }

src/ServiceControl.Monitoring/.editorconfig

@@ -2,10 +2,3 @@
 
 # Justification: Application synchronization contexts don't require ConfigureAwait(false)
 dotnet_diagnostic.CA2007.severity = none
-
-# Cancellation analyzer debt. These fire because Particular.Analyzers is no longer pinned to 0.9.0.
-# They are scheduled work, not accepted exceptions: remove a line once this project has no
-# violations of that rule left, and never add a rule back to this list.
-dotnet_diagnostic.PS0003.severity = none
-dotnet_diagnostic.PS0018.severity = none
-dotnet_diagnostic.PS0019.severity = none

src/ServiceControl.Monitoring/Hosting/Commands/AbstractCommand.cs

@@ -1,9 +1,10 @@
 namespace ServiceControl.Monitoring
 {
+    using System.Threading;
     using System.Threading.Tasks;
 
     abstract class AbstractCommand
     {
-        public abstract Task Execute(HostArguments args, Settings settings);
+        public abstract Task Execute(HostArguments args, Settings settings, CancellationToken cancellationToken = default);
     }
 }

src/ServiceControl.Monitoring/Hosting/Commands/CommandRunner.cs

@@ -1,14 +1,15 @@
 namespace ServiceControl.Monitoring
 {
     using System;
+    using System.Threading;
     using System.Threading.Tasks;
 
     class CommandRunner(Type commandType)
     {
-        public async Task Execute(HostArguments args, Settings settings)
+        public async Task Execute(HostArguments args, Settings settings, CancellationToken cancellationToken = default)
         {
             var command = (AbstractCommand)Activator.CreateInstance(commandType);
-            await command.Execute(args, settings);
+            await command.Execute(args, settings, cancellationToken);
         }
     }
 }

src/ServiceControl.Monitoring/Hosting/Commands/RunCommand.cs

@@ -1,5 +1,6 @@
 namespace ServiceControl.Monitoring
 {
+    using System.Threading;
     using System.Threading.Tasks;
     using Infrastructure;
     using Infrastructure.WebApi;
@@ -10,7 +11,7 @@ namespace ServiceControl.Monitoring
 
     class RunCommand : AbstractCommand
     {
-        public override async Task Execute(HostArguments args, Settings settings)
+        public override async Task Execute(HostArguments args, Settings settings, CancellationToken cancellationToken = default)
         {
             var endpointConfiguration = new EndpointConfiguration(settings.InstanceName);
 

src/ServiceControl.Monitoring/Hosting/Commands/SetupCommand.cs

@@ -1,13 +1,14 @@
 namespace ServiceControl.Monitoring
 {
+    using System.Threading;
     using System.Threading.Tasks;
     using Microsoft.Extensions.Logging;
     using ServiceControl.Infrastructure;
     using Transports;
 
     class SetupCommand : AbstractCommand
     {
-        public override Task Execute(HostArguments args, Settings settings)
+        public override Task Execute(HostArguments args, Settings settings, CancellationToken cancellationToken = default)
         {
             if (args.SkipQueueCreation)
             {
@@ -18,7 +19,7 @@ public override Task Execute(HostArguments args, Settings settings)
             var transportSettings = settings.ToTransportSettings();
             transportSettings.ErrorQueue = settings.ErrorQueue;
             var transportCustomization = TransportFactory.Create(transportSettings);
-            return transportCustomization.ProvisionQueues(transportSettings, []);
+            return transportCustomization.ProvisionQueues(transportSettings, [], cancellationToken);
         }
     }
 }

src/ServiceControl.Monitoring/Infrastructure/RemoveExpiredEndpointInstances.cs

@@ -17,7 +17,7 @@ public class RemoveExpiredEndpointInstances(
 {
     const int IntervalInMinutes = 5;
 
-    protected override async Task ExecuteAsync(CancellationToken cancellationToken)
+    protected override async Task ExecuteAsync(CancellationToken cancellationToken = default)
     {
         logger.LogInformation($"Starting {nameof(RemoveExpiredEndpointInstances)}");
 

src/ServiceControl.Monitoring/Infrastructure/ReportThroughputHostedService.cs

@@ -13,7 +13,7 @@
 
     class ReportThroughputHostedService(ILogger<ReportThroughputHostedService> logger, IMessageSession session, IEndpointMetricsApi endpointMetricsApi, Settings settings, TimeProvider timeProvider, ITransportCustomization transportCustomization) : BackgroundService
     {
-        protected override async Task ExecuteAsync(CancellationToken cancellationToken)
+        protected override async Task ExecuteAsync(CancellationToken cancellationToken = default)
         {
             logger.LogInformation($"Starting {nameof(ReportThroughputHostedService)}");
 
@@ -29,7 +29,10 @@ protected override async Task ExecuteAsync(CancellationToken cancellationToken)
                     {
                         await ReportOnThroughput(serviceControlThroughputDataQueue, cancellationToken);
                     }
+#pragma warning disable PS0019 // The filter already excludes OperationCanceledException, so cancellation
+                    // is left to the outer handler.
                     catch (Exception ex) when (ex is not OperationCanceledException)
+#pragma warning restore PS0019
                     {
                         if (ex.InnerException is not null and QueueNotFoundException)
                         {

src/ServiceControl.Monitoring/Licensing/LicenseCheckHostedService.cs

@@ -9,7 +9,7 @@
 
     class LicenseCheckHostedService(ActiveLicense activeLicense, IAsyncTimer scheduler, ILogger<LicenseCheckHostedService> logger) : IHostedService
     {
-        public Task StartAsync(CancellationToken cancellationToken)
+        public Task StartAsync(CancellationToken cancellationToken = default)
         {
             var due = TimeSpan.FromHours(8);
             timer = scheduler.Schedule(_ =>
@@ -20,7 +20,7 @@ public Task StartAsync(CancellationToken cancellationToken)
             return Task.CompletedTask;
         }
 
-        public Task StopAsync(CancellationToken cancellationToken) => timer.Stop(cancellationToken);
+        public Task StopAsync(CancellationToken cancellationToken = default) => timer.Stop(cancellationToken);
 
         TimerJob timer;