Add logs when connection or write requests fails

src/NBomber.Sinks.OpenTelemetry/OpenTelemetrySdkEventListener.cs

@@ -0,0 +1,38 @@
+using System.Diagnostics.Tracing;
+using Serilog;
+
+namespace NBomber.Sinks.OpenTelemetry;
+
+internal class OpenTelemetrySdkEventListener : EventListener
+{
+    private readonly ILogger _logger;
+
+    public OpenTelemetrySdkEventListener(ILogger logger)
+    {
+        _logger = logger;
+    }
+
+    protected override void OnEventSourceCreated(EventSource eventSource)
+    {
+        if (eventSource.Name.StartsWith("OpenTelemetry", StringComparison.OrdinalIgnoreCase))
+        {
+            EnableEvents(eventSource, EventLevel.Error);
+        }  
+    }
+
+    protected override void OnEventWritten(EventWrittenEventArgs eventData)
+    {
+        if (!eventData.EventSource.Name.StartsWith("OpenTelemetry", StringComparison.OrdinalIgnoreCase))
+            return;
+
+        var payload = eventData.Payload != null
+            ? string.Join(", ", eventData.Payload)
+            : string.Empty;
+
+        _logger.Error(
+            "OpenTelemetrySink [{Source}] {EventName}: {Payload}",
+            eventData.EventSource.Name,
+            eventData.EventName,
+            payload);
+    }
+}

src/NBomber.Sinks.OpenTelemetry/OpenTelemetrySink.cs

@@ -26,6 +26,7 @@ public class OpenTelemetrySink : IReportingSink
     private EmptyMetricsReader _customMetricsReader = null!;
     private OtlpExporterOptions _config = null!;
     private MetricReaderTemporalityPreference _readerTemporalityPreference;
+    private OpenTelemetrySdkEventListener _eventListener = null!;
 
     /// <summary>
     /// Gets the name of the sink.
@@ -65,11 +66,12 @@ public Task Init(IBaseContext context, IConfiguration infraConfig)
     {
         _logger = context.Logger.ForContext<OpenTelemetrySink>();
         _context = context;
+        _eventListener = new OpenTelemetrySdkEventListener(_logger);
 
         var config = infraConfig?.GetSection("OpenTelemetrySink").Get<OtlpExporterOptions>();
         if (config != null)
             _config = config;
-        
+
         _customMetricsReader = new EmptyMetricsReader(new OtlpMetricExporter(_config));
         _customMetricsReader.TemporalityPreference = _readerTemporalityPreference;
 
@@ -156,6 +158,7 @@ public void Dispose()
         _meterProvider.Dispose();
         _customMetricsReader.Dispose();
         _meter.Dispose();
+        _eventListener.Dispose();
     }
 
     private void RecordRealtimeStats(ScenarioStats[] stats, OperationType operationType)