Disable publish metrics during high load

Azure-Samples · Jul 30, 2024 · 50280de · 50280de
1 parent b87ce16
commit 50280de
Showing 1 changed file with 19 additions and 8 deletions.
diff --git a/src/PlcServer.cs b/src/PlcServer.cs
@@ -21,7 +21,9 @@ namespace OpcPlc;
 using System.Threading;
 
 public partial class PlcServer : StandardServer
-{
+{
+    private const uint PlcShutdownWaitSeconds = 10;
+
     public PlcNodeManager PlcNodeManager { get; set; }
 
     public AlarmConditionServerNodeManager AlarmNodeManager { get; set; }
@@ -37,7 +39,9 @@ public partial class PlcServer : StandardServer
     public readonly TimeService TimeService;
     private readonly ImmutableList<IPluginNodes> _pluginNodes;
     private readonly ILogger _logger;
-    private readonly Timer _periodicLoggingTimer;
+    private readonly Timer _periodicLoggingTimer;
+
+    private bool _disablePublishMetrics;
 
     public PlcServer(OpcPlcConfiguration config, PlcSimulation plcSimulation, TimeService timeService, ImmutableList<IPluginNodes> pluginNodes, ILogger logger)
     {
@@ -55,14 +59,20 @@ public PlcServer(OpcPlcConfiguration config, PlcSimulation plcSimulation, TimeSe
 
                     ThreadPool.GetAvailableThreads(out int availWorkerThreads, out int availCompletionPortThreads);
 
+                    int sessionCount = ServerInternal.SessionManager.GetSessions().Count;
+                    IList<Subscription> subscriptions = ServerInternal.SubscriptionManager.GetSubscriptions();
+                    int monitoredItemsCount = subscriptions.Sum(s => s.MonitoredItemCount);
+
                     LogPeriodicInfo(
-                        ServerInternal.SessionManager.GetSessions().Count,
-                        ServerInternal.SubscriptionManager.GetSubscriptions().Count,
-                        ServerInternal.SubscriptionManager.GetSubscriptions().Sum(s => s.MonitoredItemCount),
+                        sessionCount,
+                        subscriptions.Count,
+                        monitoredItemsCount,
                         curProc.WorkingSet64 / 1024 / 1024,
                         availWorkerThreads,
                         availCompletionPortThreads,
                         curProc.Threads.Count);
+
+                    _disablePublishMetrics = sessionCount > 40 || monitoredItemsCount > 500;
                 }
                 catch
                 {
@@ -209,7 +219,10 @@ public override ResponseHeader Publish(
 
             var responseHeader = base.Publish(requestHeader, subscriptionAcknowledgements, out subscriptionId, out availableSequenceNumbers, out moreNotifications, out notificationMessage, out results, out diagnosticInfos);
 
-            MetricsHelper.AddPublishedCount(context.SessionId.ToString(), subscriptionId.ToString(), notificationMessage, _logger);
+            if (!_disablePublishMetrics)
+            {
+                MetricsHelper.AddPublishedCount(context.SessionId.ToString(), subscriptionId.ToString(), notificationMessage, _logger);
+            }
 
             LogSuccessWithSessionIdAndSubscriptionId(
                 nameof(Publish),
@@ -513,8 +526,6 @@ protected override void OnServerStopping()
         base.OnServerStopping();
     }
 
-    private const uint PlcShutdownWaitSeconds = 10;
-
     [LoggerMessage(
         Level = LogLevel.Information,
         Message = "\n\t# Open sessions: {Sessions}\n" +