preventing races during specialization

Author: brettsam

src/WebJobs.Script.WebHost/Diagnostics/Extensions/ScriptHostServiceLoggerExtension.cs

@@ -12,115 +12,127 @@ public static class ScriptHostServiceLoggerExtension
 
         private static readonly Action<ILogger, Exception> _scriptHostServiceInitCanceledByRuntime =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(500, nameof(ScriptHostServiceInitCanceledByRuntime)),
-            "Initialization cancellation requested by runtime.");
+                LogLevel.Information,
+                new EventId(500, nameof(ScriptHostServiceInitCanceledByRuntime)),
+                "Initialization cancellation requested by runtime.");
 
         private static readonly Action<ILogger, int, TimeSpan, Exception> _unehealthyCountExceeded =
             LoggerMessage.Define<int, TimeSpan>(
-            LogLevel.Error,
-            new EventId(501, nameof(UnhealthyCountExceeded)),
-            "Host unhealthy count exceeds the threshold of {healthCheckThreshold} for time window {healthCheckWindow}. Initiating shutdown.");
+                LogLevel.Error,
+                new EventId(501, nameof(UnhealthyCountExceeded)),
+                "Host unhealthy count exceeds the threshold of {healthCheckThreshold} for time window {healthCheckWindow}. Initiating shutdown.");
 
         private static readonly Action<ILogger, Exception> _offline =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(502, nameof(Offline)),
-            "Host is offline.");
+                LogLevel.Information,
+                new EventId(502, nameof(Offline)),
+                "Host is offline.");
 
         private static readonly Action<ILogger, Exception> _initializing =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(503, nameof(Initializing)),
-            "Initializing Host.");
+                LogLevel.Information,
+                new EventId(503, nameof(Initializing)),
+                "Initializing Host.");
 
         private static readonly Action<ILogger, int, int, Exception> _initialization =
             LoggerMessage.Define<int, int>(
-            LogLevel.Information,
-            new EventId(504, nameof(Initialization)),
-            "Host initialization: ConsecutiveErrors={attemptCount}, StartupCount={startCount}");
+                LogLevel.Information,
+                new EventId(504, nameof(Initialization)),
+                "Host initialization: ConsecutiveErrors={attemptCount}, StartupCount={startCount}");
 
         private static readonly Action<ILogger, Exception> _inStandByMode =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(505, nameof(InStandByMode)),
-            "Host is in standby mode");
+                LogLevel.Information,
+                new EventId(505, nameof(InStandByMode)),
+                "Host is in standby mode");
 
         private static readonly Action<ILogger, Exception> _unhealthyRestart =
             LoggerMessage.Define(
-            LogLevel.Error,
-            new EventId(506, nameof(UnhealthyRestart)),
-            "Host is unhealthy. Initiating a restart.");
+                LogLevel.Error,
+                new EventId(506, nameof(UnhealthyRestart)),
+                "Host is unhealthy. Initiating a restart.");
 
         private static readonly Action<ILogger, Exception> _stopping =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(507, nameof(Stopping)),
-            "Stopping host...");
+                LogLevel.Information,
+                new EventId(507, nameof(Stopping)),
+                "Stopping host...");
 
         private static readonly Action<ILogger, Exception> _didNotShutDown =
             LoggerMessage.Define(
-            LogLevel.Warning,
-            new EventId(508, nameof(DidNotShutDown)),
-            "Host did not shutdown within its allotted time.");
+                LogLevel.Warning,
+                new EventId(508, nameof(DidNotShutDown)),
+                "Host did not shutdown within its allotted time.");
 
-        private static readonly Action<ILogger,  Exception> _shutDownCompleted =
+        private static readonly Action<ILogger, Exception> _shutDownCompleted =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(509, nameof(ShutDownCompleted)),
-            "Host shutdown completed.");
+                LogLevel.Information,
+                new EventId(509, nameof(ShutDownCompleted)),
+                "Host shutdown completed.");
 
         private static readonly Action<ILogger, string, Exception> _skipRestart =
             LoggerMessage.Define<string>(
-            LogLevel.Debug,
-            new EventId(510, nameof(SkipRestart)),
-            "Host restart was requested, but current host state is '{state}'. Skipping restart.");
+                LogLevel.Debug,
+                new EventId(510, nameof(SkipRestart)),
+                "Host restart was requested, but current host state is '{state}'. Skipping restart.");
 
         private static readonly Action<ILogger, Exception> _restarting =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(511, nameof(Restarting)),
-            "Restarting host.");
+                LogLevel.Information,
+                new EventId(511, nameof(Restarting)),
+                "Restarting host.");
 
         private static readonly Action<ILogger, Exception> _restarted =
             LoggerMessage.Define(
-            LogLevel.Information,
-            new EventId(512, nameof(Restarted)),
-            "Host restarted.");
+                LogLevel.Information,
+                new EventId(512, nameof(Restarted)),
+                "Host restarted.");
 
         private static readonly Action<ILogger, string, string, Exception> _building =
             LoggerMessage.Define<string, string>(
-            LogLevel.Information,
-            new EventId(513, nameof(Building)),
-            "Building host: startup suppressed:{skipHostStartup}, configuration suppressed: {skipHostJsonConfiguration}");
+                LogLevel.Information,
+                new EventId(513, nameof(Building)),
+                "Building host: startup suppressed:{skipHostStartup}, configuration suppressed: {skipHostJsonConfiguration}");
 
         private static readonly Action<ILogger, Exception> _startupWasCanceled =
             LoggerMessage.Define(
-            LogLevel.Debug,
-            new EventId(514, nameof(StartupWasCanceled)),
-            "Host startup was canceled.");
+                LogLevel.Debug,
+                new EventId(514, nameof(StartupWasCanceled)),
+                "Host startup was canceled.");
 
         private static readonly Action<ILogger, Exception> _errorOccured =
             LoggerMessage.Define(
-            LogLevel.Debug,
-            new EventId(515, nameof(ErrorOccured)),
-            "A host error has occurred");
+                LogLevel.Error,
+                new EventId(515, nameof(ErrorOccured)),
+                "A host error has occurred");
 
         private static readonly Action<ILogger, Exception> _errorOccuredInactive =
             LoggerMessage.Define(
-            LogLevel.Debug,
-            new EventId(516, nameof(ErrorOccuredInactive)),
-            "A host error has occurred on an inactive host");
+                LogLevel.Warning,
+                new EventId(516, nameof(ErrorOccuredInactive)),
+                "A host error has occurred on an inactive host");
 
         private static readonly Action<ILogger, Exception> _cancellationRequested =
             LoggerMessage.Define(
-            LogLevel.Debug,
-            new EventId(517, nameof(CancellationRequested)),
-            "Cancellation requested. A new host will not be started.");
+                LogLevel.Debug,
+                new EventId(517, nameof(CancellationRequested)),
+                "Cancellation requested. A new host will not be started.");
+
+        private static readonly Action<ILogger, string, string, Exception> _activeHostChanging =
+            LoggerMessage.Define<string, string>(
+                LogLevel.Debug,
+                new EventId(518, nameof(ActiveHostChanging)),
+                "Active host changing from '{oldHostInstanceId}' to '{newHostInstanceId}'.");
+
+        private static readonly Action<ILogger, Exception> _enteringRestart =
+            LoggerMessage.Define(
+                LogLevel.Debug,
+                new EventId(519, nameof(EnteringRestart)),
+                "Restart requested. Cancelling any active host startup.");
 
         public static void ScriptHostServiceInitCanceledByRuntime(this ILogger logger)
         {
-           _scriptHostServiceInitCanceledByRuntime(logger, null);
+            _scriptHostServiceInitCanceledByRuntime(logger, null);
         }
 
         public static void UnhealthyCountExceeded(this ILogger logger, int healthCheckThreshold, TimeSpan healthCheckWindow)
@@ -130,22 +142,22 @@ public static void UnhealthyCountExceeded(this ILogger logger, int healthCheckTh
 
         public static void Offline(this ILogger logger)
         {
-           _offline(logger, null);
+            _offline(logger, null);
         }
 
         public static void Initializing(this ILogger logger)
         {
-           _initializing(logger, null);
+            _initializing(logger, null);
         }
 
         public static void Initialization(this ILogger logger, int attemptCount, int startCount)
         {
-           _initialization(logger, attemptCount, startCount, null);
+            _initialization(logger, attemptCount, startCount, null);
         }
 
         public static void InStandByMode(this ILogger logger)
         {
-           _inStandByMode(logger, null);
+            _inStandByMode(logger, null);
         }
 
         public static void UnhealthyRestart(this ILogger logger)
@@ -155,7 +167,7 @@ public static void UnhealthyRestart(this ILogger logger)
 
         public static void Stopping(this ILogger logger)
         {
-           _stopping(logger, null);
+            _stopping(logger, null);
         }
 
         public static void DidNotShutDown(this ILogger logger)
@@ -165,7 +177,7 @@ public static void DidNotShutDown(this ILogger logger)
 
         public static void ShutDownCompleted(this ILogger logger)
         {
-           _shutDownCompleted(logger, null);
+            _shutDownCompleted(logger, null);
         }
 
         public static void SkipRestart(this ILogger logger, string state)
@@ -175,17 +187,17 @@ public static void SkipRestart(this ILogger logger, string state)
 
         public static void Restarting(this ILogger logger)
         {
-           _restarting(logger, null);
+            _restarting(logger, null);
         }
 
         public static void Restarted(this ILogger logger)
         {
-           _restarted(logger, null);
+            _restarted(logger, null);
         }
 
         public static void Building(this ILogger logger, string skipHostStartup, string skipHostJsonConfiguration)
         {
-           _building(logger, skipHostStartup, skipHostJsonConfiguration, null);
+            _building(logger, skipHostStartup, skipHostJsonConfiguration, null);
         }
 
         public static void StartupWasCanceled(this ILogger logger)
@@ -207,5 +219,15 @@ public static void CancellationRequested(this ILogger logger)
         {
             _cancellationRequested(logger, null);
         }
+
+        public static void ActiveHostChanging(this ILogger logger, string oldHostInstanceId, string newHostInstanceId)
+        {
+            _activeHostChanging(logger, oldHostInstanceId, newHostInstanceId, null);
+        }
+
+        public static void EnteringRestart(this ILogger logger)
+        {
+            _enteringRestart(logger, null);
+        }
     }
 }