From b772eb988e8a519203ede3ef9dfa9c405c9d38d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Chalet?= <kevinchalet@gmail.com>
Date: Fri, 3 Jan 2025 21:32:58 +0100
Subject: [PATCH] Log a message when an unhandled exception occurs in a task
 runner

---
 src/OpenNetty/OpenNettyGatewayOptions.cs | 36 ++++++++++++++++++++++--
 src/OpenNetty/OpenNettyLogger.cs         | 12 ++++++++
 src/OpenNetty/OpenNettyWorker.cs         |  2 ++
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/src/OpenNetty/OpenNettyGatewayOptions.cs b/src/OpenNetty/OpenNettyGatewayOptions.cs
index b0628d7..d2bc491 100644
--- a/src/OpenNetty/OpenNettyGatewayOptions.cs
+++ b/src/OpenNetty/OpenNettyGatewayOptions.cs
@@ -263,9 +263,39 @@ when message.Medium is OpenNettyMedium.Bus
                                _         => TimeSpan.FromSeconds(60)
                     }),
                     MaxRetryAttempts = int.MaxValue,
-                    ShouldHandle = static arguments => ValueTask.FromResult(
-                        !arguments.Context.CancellationToken.IsCancellationRequested &&
-                        arguments.Outcome.Exception is not null)
+                    ShouldHandle = static arguments =>
+                    {
+                        if (!arguments.Context.Properties.TryGetValue(
+                            key  : new ResiliencePropertyKey<OpenNettyGateway>(nameof(OpenNettyGateway)),
+                            value: out OpenNettyGateway? gateway))
+                        {
+                            throw new InvalidOperationException(SR.GetResourceString(SR.ID0074));
+                        }
+
+                        if (!arguments.Context.Properties.TryGetValue(
+                            key  : new ResiliencePropertyKey<OpenNettyLogger<OpenNettyWorker>>(nameof(OpenNettyLogger<OpenNettyWorker>)),
+                            value: out OpenNettyLogger<OpenNettyWorker>? logger))
+                        {
+                            throw new InvalidOperationException(SR.GetResourceString(SR.ID0074));
+                        }
+
+                        if (!arguments.Context.Properties.TryGetValue(
+                            key  : new ResiliencePropertyKey<OpenNettySessionType>(nameof(OpenNettySessionType)),
+                            value: out OpenNettySessionType type))
+                        {
+                            throw new InvalidOperationException(SR.GetResourceString(SR.ID0074));
+                        }
+
+                        if (arguments.Outcome.Exception is not Exception exception)
+                        {
+                            return ValueTask.FromResult(false);
+                        }
+
+                        logger.SessionErrored(exception, gateway, type);
+
+                        // Always recreate new sessions on failed attempts, unless the operation was canceled by the worker.
+                        return ValueTask.FromResult(!arguments.Context.CancellationToken.IsCancellationRequested);
+                    }
                 })
                 .Build()
         };
diff --git a/src/OpenNetty/OpenNettyLogger.cs b/src/OpenNetty/OpenNettyLogger.cs
index 020d712..68193e3 100644
--- a/src/OpenNetty/OpenNettyLogger.cs
+++ b/src/OpenNetty/OpenNettyLogger.cs
@@ -242,4 +242,16 @@ public OpenNettyLogger(ILogger<TService> logger)
         Level = LogLevel.Error,
         Message = "An error occurred while trying to connect to the MQTT broker.")]
     public partial void MqttBrokerConnectionError(Exception exception);
+
+    /// <summary>
+    /// Logs a message indicating that an error occcured while opening a session.
+    /// </summary>
+    /// <param name="exception">The exception.</param>
+    /// <param name="gateway">The gateway.</param>
+    /// <param name="type">The session type.</param>
+    [LoggerMessage(
+        EventId = 6020,
+        Level = LogLevel.Error,
+        Message = "An error occurred while trying to open a session of type {Type} to gateway {Gateway}.")]
+    public partial void SessionErrored(Exception exception, OpenNettyGateway gateway, OpenNettySessionType type);
 }
diff --git a/src/OpenNetty/OpenNettyWorker.cs b/src/OpenNetty/OpenNettyWorker.cs
index 20d8072..1af1b06 100644
--- a/src/OpenNetty/OpenNettyWorker.cs
+++ b/src/OpenNetty/OpenNettyWorker.cs
@@ -67,6 +67,7 @@ async Task CreateSharedSessionWorkerAsync(OpenNettyGateway gateway, OpenNettySes
         {
             var context = ResilienceContextPool.Shared.Get(cancellationToken);
             context.Properties.Set(new ResiliencePropertyKey<OpenNettyGateway>(nameof(OpenNettyGateway)), gateway);
+            context.Properties.Set(new ResiliencePropertyKey<OpenNettyLogger<OpenNettyWorker>>(nameof(OpenNettyLogger<OpenNettyWorker>)), _logger);
             context.Properties.Set(new ResiliencePropertyKey<OpenNettySessionType>(nameof(OpenNettySessionType)), type);
 
             _logger.TaskRunnerScheduled(gateway, type);
@@ -134,6 +135,7 @@ async Task CreateAdHocSessionWorkerAsync(
         {
             var context = ResilienceContextPool.Shared.Get(cancellationToken);
             context.Properties.Set(new ResiliencePropertyKey<OpenNettyGateway>(nameof(OpenNettyGateway)), gateway);
+            context.Properties.Set(new ResiliencePropertyKey<OpenNettyLogger<OpenNettyWorker>>(nameof(OpenNettyLogger<OpenNettyWorker>)), _logger);
             context.Properties.Set(new ResiliencePropertyKey<OpenNettySessionType>(nameof(OpenNettySessionType)), type);
 
             _logger.TaskRunnerScheduled(gateway, type);