feat: Implement Application Insights telemetry client for event tracking

Author: Harmanpreet-Microsoft

src/backend/api/event_utils.py

@@ -3,39 +3,67 @@
 import os
 
 # Third-party
-from opentelemetry import trace
-from opentelemetry.trace import Status, StatusCode
+from applicationinsights import TelemetryClient
+from applicationinsights.channel import SynchronousSender, SynchronousQueue, TelemetryChannel
 
 from dotenv import load_dotenv
 
 load_dotenv()
 
+# Global telemetry client (initialized once)
+_telemetry_client = None
+
+
+def _get_telemetry_client():
+    """Get or create the Application Insights telemetry client."""
+    global _telemetry_client
+    
+    if _telemetry_client is None:
+        connection_string = os.getenv("APPLICATIONINSIGHTS_CONNECTION_STRING")
+        if connection_string:
+            try:
+                # Extract instrumentation key from connection string
+                # Format: InstrumentationKey=xxx;IngestionEndpoint=https://...
+                parts = dict(part.split('=', 1) for part in connection_string.split(';') if '=' in part)
+                instrumentation_key = parts.get('InstrumentationKey')
+                
+                if instrumentation_key:
+                    # Create a synchronous channel for immediate sending
+                    sender = SynchronousSender()
+                    queue = SynchronousQueue(sender)
+                    channel = TelemetryChannel(None, queue)
+                    
+                    _telemetry_client = TelemetryClient(instrumentation_key, channel)
+                    logging.info("Application Insights TelemetryClient initialized successfully")
+                else:
+                    logging.error("Could not extract InstrumentationKey from connection string")
+            except Exception as e:
+                logging.error(f"Failed to initialize TelemetryClient: {e}")
+    
+    return _telemetry_client
+
 
 def track_event_if_configured(event_name: str, event_data: dict):
-    """Track a custom event using OpenTelemetry.
+    """Track a custom event to Application Insights customEvents table.
     
-    This creates a span with the event name and adds the event data as attributes.
-    The span will appear in Application Insights as a dependency with the event data.
+    This uses the Application Insights SDK TelemetryClient which properly
+    sends custom events to the customEvents table in Application Insights.
     """
     instrumentation_key = os.getenv("APPLICATIONINSIGHTS_CONNECTION_STRING")
     if instrumentation_key:
         try:
-            tracer = trace.get_tracer(__name__)
-            with tracer.start_as_current_span(f"event:{event_name}") as span:
-                # Set span kind to internal for custom events
-                span.set_attribute("event.name", event_name)
-                span.set_attribute("event.type", "custom")
-                
-                # Add all event data as span attributes
-                for key, value in event_data.items():
-                    # Convert value to string to ensure it's serializable
-                    span.set_attribute(f"event.{key}", str(value))
+            client = _get_telemetry_client()
+            if client:
+                # Convert all values to strings to ensure compatibility
+                properties = {k: str(v) for k, v in event_data.items()}
 
-                # Add event to the span (appears in Application Insights)
-                span.add_event(event_name, attributes=event_data)
-                span.set_status(Status(StatusCode.OK))
+                # Track the custom event
+                client.track_event(event_name, properties=properties)
+                client.flush()  # Ensure immediate sending
 
-                logging.debug(f"Tracked event: {event_name} with data: {event_data}")
+                logging.debug(f"Tracked custom event: {event_name} with data: {event_data}")
+            else:
+                logging.warning("TelemetryClient not available, custom event not tracked")
         except Exception as e:
             logging.error(f"Failed to track event {event_name}: {e}")
     else:

src/backend/requirements.txt

@@ -44,7 +44,7 @@ starlette
 aiortc
 opentelemetry-exporter-otlp-proto-grpc
 opentelemetry-exporter-otlp-proto-http
-azure-monitor-events-extension
+applicationinsights
 opentelemetry-sdk==1.39.0
 opentelemetry-api==1.39.0
 opentelemetry-semantic-conventions==0.60b0