Health check results are stored in memory and updated as required

src/NzbDrone.Api/Health/HealthModule.cs

@@ -8,7 +8,7 @@ using NzbDrone.Core.Messaging.Events;
 namespace NzbDrone.Api.Health
 {
     public class HealthModule : NzbDroneRestModuleWithSignalR<HealthResource, HealthCheck>,
-                                IHandle<TriggerHealthCheckEvent>
+                                IHandle<HealthCheckCompleteEvent>
     {
         private readonly IHealthCheckService _healthCheckService;
 
@@ -21,10 +21,10 @@ namespace NzbDrone.Api.Health
 
         private List<HealthResource> GetHealth()
         {
-            return ToListResource(_healthCheckService.PerformHealthCheck);
+            return ToListResource(_healthCheckService.Results);
         }
 
-        public void Handle(TriggerHealthCheckEvent message)
+        public void Handle(HealthCheckCompleteEvent message)
         {
             BroadcastResourceChange(ModelAction.Sync);
         }

src/NzbDrone.Api/Health/HealthResource.cs

@@ -2,12 +2,11 @@
 using NzbDrone.Api.REST;
 using NzbDrone.Core.HealthCheck;
 
-
 namespace NzbDrone.Api.Health
 {
     public class HealthResource : RestResource
     {
-        public HealthCheckResultType Type { get; set; }
+        public HealthCheckResult Type { get; set; }
         public String Message { get; set; }
     }
 }

src/NzbDrone.Api/NzbDrone.Api.csproj

@@ -136,7 +136,7 @@
     <Compile Include="Frontend\Mappers\IMapHttpRequestsToDisk.cs" />
     <Compile Include="Frontend\Mappers\StaticResourceMapperBase.cs" />
     <Compile Include="Frontend\StaticResourceModule.cs" />
-    <Compile Include="Health\HistoryResource.cs" />
+    <Compile Include="Health\HealthResource.cs" />
     <Compile Include="Health\HealthModule.cs" />
     <Compile Include="History\HistoryResource.cs" />
     <Compile Include="History\HistoryModule.cs" />

src/NzbDrone.Core.Test/HealthCheck/Checks/DownloadClientCheckFixture.cs

@@ -37,7 +37,7 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
         }
 
         [Test]
-        public void should_return_null_when_download_client_returns()
+        public void should_return_ok_when_download_client_returns()
         {
             var downloadClient = Mocker.GetMock<IDownloadClient>();
 
@@ -48,7 +48,7 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
                   .Setup(s => s.GetDownloadClient())
                   .Returns(downloadClient.Object);
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
     }
 }

src/NzbDrone.Core.Test/HealthCheck/Checks/DroneFactoryCheckFixture.cs

@@ -57,11 +57,11 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
         }
 
         [Test]
-        public void should_return_null_when_no_issues_found()
+        public void should_return_ok_when_no_issues_found()
         {
             GivenDroneFactoryFolder(true);
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
     }
 }

src/NzbDrone.Core.Test/HealthCheck/Checks/HealthCheckFixtureExtentions.cs

@@ -5,14 +5,19 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
 {
     public static class HealthCheckFixtureExtensions
     {
+        public static void ShouldBeOk(this Core.HealthCheck.HealthCheck result)
+        {
+            result.Type.Should().Be(HealthCheckResult.Ok);
+        }
+
         public static void ShouldBeWarning(this Core.HealthCheck.HealthCheck result)
         {
-            result.Type.Should().Be(HealthCheckResultType.Warning);
+            result.Type.Should().Be(HealthCheckResult.Warning);
         }
 
         public static void ShouldBeError(this Core.HealthCheck.HealthCheck result)
         {
-            result.Type.Should().Be(HealthCheckResultType.Error);
+            result.Type.Should().Be(HealthCheckResult.Error);
         }
     }
 }

src/NzbDrone.Core.Test/HealthCheck/Checks/IndexerCheckFixture.cs

@@ -39,7 +39,7 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
         }
 
         [Test]
-        public void should_return_null_when_multiple_indexers_are_enabled()
+        public void should_return_ok_when_multiple_indexers_are_enabled()
         {
             var indexer1 = Mocker.GetMock<IIndexer>();
             indexer1.SetupGet(s => s.SupportsSearching).Returns(true);
@@ -51,11 +51,11 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
                   .Setup(s => s.GetAvailableProviders())
                   .Returns(new List<IIndexer> { indexer1.Object, indexer2.Object });
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
 
         [Test]
-        public void should_return_null_when_indexer_supports_searching()
+        public void should_return_ok_when_indexer_supports_searching()
         {
             var indexer1 = Mocker.GetMock<IIndexer>();
             indexer1.SetupGet(s => s.SupportsSearching).Returns(true);
@@ -64,7 +64,7 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
                   .Setup(s => s.GetAvailableProviders())
                   .Returns(new List<IIndexer> { indexer1.Object });
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
     }
 }

src/NzbDrone.Core.Test/HealthCheck/Checks/MonoVersionCheckFixture.cs

@@ -48,35 +48,35 @@ namespace NzbDrone.Core.Test.HealthCheck.Checks
         }
 
         [Test]
-        public void should_return_null_when_mono_3_2()
+        public void should_return_ok_when_mono_3_2()
         {
             GivenOutput("3.2.0.1");
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
 
         [Test]
-        public void should_return_null_when_mono_4_0()
+        public void should_return_ok_when_mono_4_0()
         {
             GivenOutput("4.0.0.0");
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
 
         [Test]
-        public void should_return_null_when_mono_3_2_7()
+        public void should_return_ok_when_mono_3_2_7()
         {
             GivenOutput("3.2.7");
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
 
         [Test]
-        public void should_return_null_when_mono_3_2_1()
+        public void should_return_ok_when_mono_3_2_1()
         {
             GivenOutput("3.2.1");
 
-            Subject.Check().Should().BeNull();
+            Subject.Check().ShouldBeOk();
         }
     }
 }

src/NzbDrone.Core/Download/FailedDownloadService.cs

@@ -42,7 +42,7 @@ namespace NzbDrone.Core.Download
             _configService = configService;
             _logger = logger;
 
-            _failedDownloads = cacheManager.GetCache<FailedDownload>(GetType(), "queue");
+            _failedDownloads = cacheManager.GetCache<FailedDownload>(GetType());
         }
 
         public void MarkAsFailed(int historyId)

src/NzbDrone.Core/HealthCheck/Checks/DownloadClientCheck.cs

@@ -3,7 +3,7 @@ using NzbDrone.Core.Download;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
-    public class DownloadClientCheck : IProvideHealthCheck
+    public class DownloadClientCheck : HealthCheckBase
     {
         private readonly IProvideDownloadClient _downloadClientProvider;
 
@@ -12,13 +12,13 @@ namespace NzbDrone.Core.HealthCheck.Checks
             _downloadClientProvider = downloadClientProvider;
         }
 
-        public HealthCheck Check()
+        public override HealthCheck Check()
         {
             var downloadClient = _downloadClientProvider.GetDownloadClient();
 
             if (downloadClient == null)
             {
-                return new HealthCheck(HealthCheckResultType.Warning, "No download client is available");
+                return new HealthCheck(GetType(), HealthCheckResult.Warning, "No download client is available");
             }
 
             try
@@ -27,10 +27,10 @@ namespace NzbDrone.Core.HealthCheck.Checks
             }
             catch (Exception)
             {
-                return new HealthCheck(HealthCheckResultType.Error, "Unable to communicate with download client");
+                return new HealthCheck(GetType(), HealthCheckResult.Error, "Unable to communicate with download client");
             }
 
-            return null;
+            return new HealthCheck(GetType());
         }
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/DroneFactoryCheck.cs

@@ -6,7 +6,7 @@ using NzbDrone.Core.Configuration;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
-    public class DroneFactoryCheck : IProvideHealthCheck
+    public class DroneFactoryCheck : HealthCheckBase
     {
         private readonly IConfigService _configService;
         private readonly IDiskProvider _diskProvider;
@@ -17,18 +17,18 @@ namespace NzbDrone.Core.HealthCheck.Checks
             _diskProvider = diskProvider;
         }
 
-        public HealthCheck Check()
+        public override HealthCheck Check()
         {
             var droneFactoryFolder = _configService.DownloadedEpisodesFolder;
 
             if (droneFactoryFolder.IsNullOrWhiteSpace())
             {
-                return new HealthCheck(HealthCheckResultType.Warning, "Drone factory folder is not configured");
+                return new HealthCheck(GetType(), HealthCheckResult.Warning, "Drone factory folder is not configured");
             }
 
             if (!_diskProvider.FolderExists(droneFactoryFolder))
             {
-                return new HealthCheck(HealthCheckResultType.Error, "Drone factory folder does not exist");
+                return new HealthCheck(GetType(), HealthCheckResult.Error, "Drone factory folder does not exist");
             }
             
             try
@@ -39,12 +39,12 @@ namespace NzbDrone.Core.HealthCheck.Checks
             }
             catch (Exception)
             {
-                return new HealthCheck(HealthCheckResultType.Error, "Unable to write to drone factory folder");
+                return new HealthCheck(GetType(), HealthCheckResult.Error, "Unable to write to drone factory folder");
             }
 
             //Todo: Unable to import one or more files/folders from
 
-            return null;
+            return new HealthCheck(GetType());
         }
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/IndexerCheck.cs

@@ -3,7 +3,7 @@ using NzbDrone.Core.Indexers;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
-    public class IndexerCheck : IProvideHealthCheck
+    public class IndexerCheck : HealthCheckBase
     {
         private readonly IIndexerFactory _indexerFactory;
 
@@ -12,21 +12,21 @@ namespace NzbDrone.Core.HealthCheck.Checks
             _indexerFactory = indexerFactory;
         }
 
-        public HealthCheck Check()
+        public override HealthCheck Check()
         {
             var enabled = _indexerFactory.GetAvailableProviders();
 
             if (!enabled.Any())
             {
-                return new HealthCheck(HealthCheckResultType.Error, "No indexers are enabled");
+                return new HealthCheck(GetType(), HealthCheckResult.Error, "No indexers are enabled");
             }
 
             if (enabled.All(i => i.SupportsSearching == false))
             {
-                return new HealthCheck(HealthCheckResultType.Warning, "Enabled indexers do not support searching");
+                return new HealthCheck(GetType(), HealthCheckResult.Warning, "Enabled indexers do not support searching");
             }
 
-            return null;
+            return new HealthCheck(GetType());
         }
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/MonoVersionCheck.cs

@@ -6,7 +6,7 @@ using NzbDrone.Common.Processes;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
-    public class MonoVersionCheck : IProvideHealthCheck
+    public class MonoVersionCheck : HealthCheckBase
     {
         private readonly IProcessProvider _processProvider;
         private readonly Logger _logger;
@@ -18,11 +18,11 @@ namespace NzbDrone.Core.HealthCheck.Checks
             _logger = logger;
         }
 
-        public HealthCheck Check()
+        public override HealthCheck Check()
         {
             if (!OsInfo.IsMono)
             {
-                return null;
+                return new HealthCheck(GetType());
             }
 
             var output = _processProvider.StartAndCapture("mono", "--version");
@@ -38,12 +38,28 @@ namespace NzbDrone.Core.HealthCheck.Checks
                     if (version >= new Version(3, 2))
                     {
                         _logger.Debug("mono version is 3.2 or better: {0}", version.ToString());
-                        return null;
+                        return new HealthCheck(GetType());
                     }
                 }
             }
 
-            return new HealthCheck(HealthCheckResultType.Warning, "mono version is less than 3.2, upgrade for improved stability");
+            return new HealthCheck(GetType(), HealthCheckResult.Warning, "mono version is less than 3.2, upgrade for improved stability");
+        }
+
+        public override bool CheckOnConfigChange
+        {
+            get
+            {
+                return false;
+            }
+        }
+
+        public override bool CheckOnSchedule
+        {
+            get
+            {
+                return false;
+            }
         }
     }
 }

src/NzbDrone.Core/HealthCheck/Checks/UpdateCheck.cs

@@ -6,7 +6,7 @@ using NzbDrone.Core.Update;
 
 namespace NzbDrone.Core.HealthCheck.Checks
 {
-    public class UpdateCheck : IProvideHealthCheck
+    public class UpdateCheck : HealthCheckBase
     {
         private readonly IDiskProvider _diskProvider;
         private readonly IAppFolderInfo _appFolderInfo;
@@ -20,7 +20,7 @@ namespace NzbDrone.Core.HealthCheck.Checks
         }
 
 
-        public HealthCheck Check()
+        public override HealthCheck Check()
         {
             if (OsInfo.IsWindows)
             {
@@ -32,7 +32,7 @@ namespace NzbDrone.Core.HealthCheck.Checks
                 }
                 catch (Exception)
                 {
-                    return new HealthCheck(HealthCheckResultType.Error,
+                    return new HealthCheck(GetType(), HealthCheckResult.Error,
                         "Unable to update, running from write-protected folder");
                 }
             }
@@ -41,11 +41,19 @@ namespace NzbDrone.Core.HealthCheck.Checks
             {
                 if (_checkUpdateService.AvailableUpdate() != null)
                 {
-                    return new HealthCheck(HealthCheckResultType.Warning, "New update is available");
+                    return new HealthCheck(GetType(), HealthCheckResult.Warning, "New update is available");
                 }
             }
 
-            return null;
+            return new HealthCheck(GetType());
+        }
+
+        public override bool CheckOnConfigChange
+        {
+            get
+            {
+                return false;
+            }
         }
     }
 }

src/NzbDrone.Core/HealthCheck/HealthCheck.cs

@@ -5,18 +5,27 @@ namespace NzbDrone.Core.HealthCheck
 {
     public class HealthCheck : ModelBase
     {
-        public HealthCheckResultType Type { get; set; }
+        public Type Source { get; set; }
+        public HealthCheckResult Type { get; set; }
         public String Message { get; set; }
 
-        public HealthCheck(HealthCheckResultType type, string message)
+        public HealthCheck(Type source)
         {
+            Source = source;
+            Type = HealthCheckResult.Ok;
+        }
+
+        public HealthCheck(Type source, HealthCheckResult type, string message)
+        {
+            Source = source;
             Type = type;
             Message = message;
         }
     }
 
-    public enum HealthCheckResultType
+    public enum HealthCheckResult
     {
+        Ok = 0,
         Warning = 1,
         Error = 2
     }

src/NzbDrone.Core/HealthCheck/HealthCheckBase.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NzbDrone.Core.HealthCheck
+{
+    public abstract class HealthCheckBase : IProvideHealthCheck
+    {
+        public abstract HealthCheck Check();
+
+        public virtual bool CheckOnStartup
+        {
+            get
+            {
+                return true;
+            }
+        }
+
+        public virtual bool CheckOnConfigChange
+        {
+            get
+            {
+                return true;
+            }
+        }
+
+        public virtual bool CheckOnSchedule
+        {
+            get
+            {
+                return true;
+            }
+        }
+    }
+}

src/NzbDrone.Core/HealthCheck/HealthCheckCompleteEvent.cs

@@ -2,7 +2,7 @@
 
 namespace NzbDrone.Core.HealthCheck
 {
-    public class TriggerHealthCheckEvent : IEvent
+    public class HealthCheckCompleteEvent : IEvent
     {
     }
 }

src/NzbDrone.Core/HealthCheck/HealthCheckService.cs

@@ -1,9 +1,13 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
+using System.Linq.Expressions;
 using NLog;
+using NzbDrone.Common.Cache;
 using NzbDrone.Core.Configuration.Events;
 using NzbDrone.Core.Download;
 using NzbDrone.Core.Indexers;
+using NzbDrone.Core.Lifecycle;
 using NzbDrone.Core.Messaging.Commands;
 using NzbDrone.Core.Messaging.Events;
 using NzbDrone.Core.ThingiProvider.Events;
@@ -12,56 +16,86 @@ namespace NzbDrone.Core.HealthCheck
 {
     public interface IHealthCheckService
     {
-        List<HealthCheck> PerformHealthCheck();
+        List<HealthCheck> Results();
     }
 
     public class HealthCheckService : IHealthCheckService,
                                       IExecute<CheckHealthCommand>,
+                                      IHandleAsync<ApplicationStartedEvent>,
                                       IHandleAsync<ConfigSavedEvent>,
                                       IHandleAsync<ProviderUpdatedEvent<IIndexer>>,
                                       IHandleAsync<ProviderUpdatedEvent<IDownloadClient>>
     {
         private readonly IEnumerable<IProvideHealthCheck> _healthChecks;
         private readonly IEventAggregator _eventAggregator;
+        private readonly ICacheManager _cacheManager;
         private readonly Logger _logger;
 
-        public HealthCheckService(IEnumerable<IProvideHealthCheck> healthChecks, IEventAggregator eventAggregator, Logger logger)
+        private readonly ICached<HealthCheck> _healthCheckResults;
+
+        public HealthCheckService(IEnumerable<IProvideHealthCheck> healthChecks,
+                                  IEventAggregator eventAggregator,
+                                  ICacheManager cacheManager,
+                                  Logger logger)
         {
             _healthChecks = healthChecks;
             _eventAggregator = eventAggregator;
+            _cacheManager = cacheManager;
             _logger = logger;
+
+            _healthCheckResults = _cacheManager.GetCache<HealthCheck>(GetType());
+        }
+
+        public List<HealthCheck> Results()
+        {
+            return _healthCheckResults.Values.ToList();
         }
 
-        public List<HealthCheck> PerformHealthCheck()
+        private void PerformHealthCheck(Func<IProvideHealthCheck, bool> predicate)
         {
-            _logger.Trace("Checking health");
+            var results = _healthChecks.Where(predicate)
-            var result = _healthChecks.Select(c => c.Check()).Where(c => c != null).ToList();
+                                       .Select(c => c.Check())
+                                       .ToList();
 
-            return result;
+            foreach (var result in results)
+            {
+                if (result.Type == HealthCheckResult.Ok)
+                {
+                    _healthCheckResults.Remove(result.Source.Name);
                 }
 
-        public void Execute(CheckHealthCommand message)
+                else
                 {
-            //Until we have stored health checks we should just trigger the complete event
+                    _healthCheckResults.Set(result.Source.Name, result);
-            //and let the clients check in
+                }
-            //Multiple connected clients means we're going to compute the health check multiple times
+            }
-            //Multiple checks feels a bit ugly, but means the most up to date information goes to the client
+
-            _eventAggregator.PublishEvent(new TriggerHealthCheckEvent());
+            _eventAggregator.PublishEvent(new HealthCheckCompleteEvent());
         }
 
         public void HandleAsync(ConfigSavedEvent message)
         {
-            _eventAggregator.PublishEvent(new TriggerHealthCheckEvent());
+            PerformHealthCheck(c => c.CheckOnConfigChange);
         }
 
         public void HandleAsync(ProviderUpdatedEvent<IIndexer> message)
         {
-            _eventAggregator.PublishEvent(new TriggerHealthCheckEvent());
+            PerformHealthCheck(c => c.CheckOnConfigChange);
         }
 
         public void HandleAsync(ProviderUpdatedEvent<IDownloadClient> message)
         {
-            _eventAggregator.PublishEvent(new TriggerHealthCheckEvent());
+            PerformHealthCheck(c => c.CheckOnConfigChange);
+        }
+
+        public void HandleAsync(ApplicationStartedEvent message)
+        {
+            PerformHealthCheck(c => c.CheckOnStartup);
+        }
+
+        public void Execute(CheckHealthCommand message)
+        {
+            PerformHealthCheck(c => c.CheckOnSchedule);
         }
     }
 }

src/NzbDrone.Core/HealthCheck/IProvideHealthCheck.cs

@@ -1,7 +1,12 @@
-namespace NzbDrone.Core.HealthCheck
+using System;
+
+namespace NzbDrone.Core.HealthCheck
 {
     public interface IProvideHealthCheck
     {
         HealthCheck Check();
+        Boolean CheckOnStartup { get; }
+        Boolean CheckOnConfigChange { get; }
+        Boolean CheckOnSchedule { get; }
     }
 }

src/NzbDrone.Core/Jobs/TaskManager.cs

@@ -50,10 +50,10 @@ namespace NzbDrone.Core.Jobs
                 {
                     new ScheduledTask{ Interval = 1, TypeName = typeof(TrackedCommandCleanupCommand).FullName},
                     new ScheduledTask{ Interval = 1, TypeName = typeof(CheckForFailedDownloadCommand).FullName},
-                    new ScheduledTask{ Interval = 5, TypeName = typeof(CheckHealthCommand).FullName},
                     new ScheduledTask{ Interval = 1*60, TypeName = typeof(ApplicationUpdateCommand).FullName},
                     new ScheduledTask{ Interval = 1*60, TypeName = typeof(TrimLogCommand).FullName},
                     new ScheduledTask{ Interval = 3*60, TypeName = typeof(UpdateSceneMappingCommand).FullName},
+                    new ScheduledTask{ Interval = 6*60, TypeName = typeof(CheckHealthCommand).FullName},
                     new ScheduledTask{ Interval = 12*60, TypeName = typeof(RefreshSeriesCommand).FullName},
                     new ScheduledTask{ Interval = 24*60, TypeName = typeof(HousekeepingCommand).FullName},
 

src/NzbDrone.Core/NzbDrone.Core.csproj

@@ -280,7 +280,8 @@
     <Compile Include="HealthCheck\Checks\IndexerCheck.cs" />
     <Compile Include="HealthCheck\Checks\UpdateCheck.cs" />
     <Compile Include="HealthCheck\HealthCheck.cs" />
-    <Compile Include="HealthCheck\TriggerHealthCheckEvent.cs" />
+    <Compile Include="HealthCheck\HealthCheckBase.cs" />
+    <Compile Include="HealthCheck\HealthCheckCompleteEvent.cs" />
     <Compile Include="Housekeeping\Housekeepers\CleanupOrphanedEpisodes.cs" />
     <Compile Include="Housekeeping\Housekeepers\CleanupOrphanedHistoryItems.cs" />
     <Compile Include="Housekeeping\Housekeepers\CleanupOrphanedMetadataFiles.cs" />