Improve Telemetry singleton with thread safety and resource cleanup

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/telemetry/telemetry.py

@@ -4,6 +4,7 @@ import asyncio
 import json
 import os
 import platform
+import threading
 import warnings
 from contextlib import contextmanager
 from importlib.metadata import version
@@ -42,13 +43,26 @@ class Telemetry:
 
     Users can opt-in to sharing more complete data using the `share_crew`
     attribute in the Crew class.
+
+    This class implements a singleton pattern to ensure that only one instance
+    of the telemetry system exists, preventing multiple OtelBatchSpanProcessor
+    threads from being created. This is particularly important in environments
+    like FastAPI endpoints where agents are created dynamically, as it prevents
+    resource leaks and excessive thread creation.
+
+    The implementation uses thread-safe double-checked locking to ensure
+    thread safety when multiple threads attempt to create a Telemetry instance
+    simultaneously.
     """
     _instance = None
     _initialized = False
+    _instance_lock = threading.Lock()
 
     def __new__(cls):
         if cls._instance is None:
-            cls._instance = super().__new__(cls)
+            with cls._instance_lock:
+                if cls._instance is None:
+                    cls._instance = super().__new__(cls)
         return cls._instance
 
     def __init__(self):
@@ -87,6 +101,16 @@ class Telemetry:
             
             self._initialized = True
 
+    def __del__(self):
+        """Clean up resources when the instance is destroyed."""
+        if hasattr(self, 'provider') and self.provider:
+            try:
+                self.provider.shutdown()
+            except Exception as e:
+                # Re-raise the exception to not interfere with system signals
+                if isinstance(e, (SystemExit, KeyboardInterrupt, GeneratorExit, asyncio.CancelledError)):
+                    raise
+
     def set_tracer(self):
         if self.ready and not self.trace_set:
             try: