From 2687c98f63255c289e5765a729da35ac9dee7dff Mon Sep 17 00:00:00 2001
From: lemaitre-aneo <flemaitre@aneo.fr>
Date: Wed, 17 Apr 2024 16:07:03 +0200
Subject: [PATCH] Add oldest started time gauge

---
 Common/src/Pollster/Pollster.cs    | 22 ++++++++++++++++++++++
 Common/src/Pollster/TaskHandler.cs |  5 +++++
 2 files changed, 27 insertions(+)

diff --git a/Common/src/Pollster/Pollster.cs b/Common/src/Pollster/Pollster.cs
index cc1610dbb..98f75315c 100644
--- a/Common/src/Pollster/Pollster.cs
+++ b/Common/src/Pollster/Pollster.cs
@@ -132,6 +132,28 @@ public Pollster(IPullQueueStorage          pullQueueStorage,
                                                                "Tasks",
                                                                "Number of tasks in the pipeline",
                                                                meterHolder_.Tags);
+
+    meterHolder.Meter.CreateObservableGauge("TaskRunningTime",
+                                            () => taskProcessingDict_.Values.MinBy(taskHandler => taskHandler.StartedAt) switch
+                                                  {
+                                                    null => 0.0,
+                                                    // ReSharper disable once PatternAlwaysMatches
+                                                    TaskHandler taskHandler => (DateTime.UtcNow - taskHandler.StartedAt).TotalMilliseconds,
+                                                  },
+                                            "Milliseconds",
+                                            "Running time of the oldest task still processing by the Pollster",
+                                            meterHolder_.Tags);
+
+    meterHolder.Meter.CreateObservableGauge("TaskStartTime",
+                                            () => (taskProcessingDict_.Values.MinBy(taskHandler => taskHandler.StartedAt) switch
+                                                   {
+                                                     null => TimeSpan.MaxValue,
+                                                     // ReSharper disable once PatternAlwaysMatches
+                                                     TaskHandler taskHandler => taskHandler.StartedAt - DateTime.UnixEpoch,
+                                                   }).TotalSeconds,
+                                            "Seconds",
+                                            "Start time of the oldest task still processing by the Pollster",
+                                            meterHolder_.Tags);
   }
 
   public ICollection<string> TaskProcessing
diff --git a/Common/src/Pollster/TaskHandler.cs b/Common/src/Pollster/TaskHandler.cs
index e8504befb..294752965 100644
--- a/Common/src/Pollster/TaskHandler.cs
+++ b/Common/src/Pollster/TaskHandler.cs
@@ -142,6 +142,11 @@ public TaskHandler(ISessionTable                         sessionTable,
     registration2_ = workerConnectionCts_.Token.Register(() => logger_.LogWarning("Cancellation triggered, start to properly cancel task"));
   }
 
+  /// <summary>
+  ///   Start date for the task handled by the current Task Handler
+  /// </summary>
+  public DateTime StartedAt { get; } = DateTime.UtcNow;
+
 
   /// <inheritdoc />
   public async ValueTask DisposeAsync()