add life span manager to guarantee graceful db shutdown

self_hosted_env/voice_agent/services/agent_service.py

@@ -293,6 +293,3 @@ class AgentService:
             except Exception as e:
                 logger.error(f"Error closing connection pools: {e}")
 
-    def __del__(self):
-        """Destructor to ensure connection pools are closed"""
-        self.close()
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self_hosted_env/voice_agent/services/response_manager.py

@@ -40,43 +40,44 @@ class ResponseManager:
 
     def get_response(self, student_id: str) -> Dict:
         """
-        Atomically gets the response for a student and removes it from Redis
-        to ensure it's claimed only once.
+        Gets the response for a student without deleting it.
+        This allows the client to safely retry the request if it fails.
+        The key will be cleaned up automatically by Redis when its TTL expires.
         """
         key = self._get_key(student_id)
         
-        # Use a pipeline to get and delete the key in a single, atomic operation
-        pipe = self.redis.pipeline()
-        pipe.get(key)
-        pipe.delete(key)
-        results = pipe.execute()
-        json_value = results[0]
+        # 1. Use a simple, non-destructive GET command. No pipeline needed.
+        json_value = self.redis.get(key)
 
         if not json_value:
-            # If nothing was found, return the same empty structure as the old class
-            return {"text": None, "audio_filename": None, "audio_bytes": None}
+            return {"text": None, "audio_filepath": None, "audio_bytes": None}
 
-        # If data was found, decode it
+        # 2. Decode the payload as before.
         payload = json.loads(json_value)
         
-        # Decode the Base64 string back into binary audio data
         if payload.get("audio_bytes_b64"):
             payload["audio_bytes"] = base64.b64decode(payload["audio_bytes_b64"])
         else:
             payload["audio_bytes"] = None
         
-        # Remove the temporary key before returning
         del payload["audio_bytes_b64"]
         
         return payload
 
     def clear_response(self, student_id: str) -> None:
-        """Clears a response for a specific student from Redis."""
+        """
+        Clears a response for a specific student from Redis.
+        This is still important to call at the *beginning* of a new /chat request
+        to ensure old data is invalidated immediately.
+        """
         key = self._get_key(student_id)
         self.redis.delete(key)
 
-    def is_response_fresh(self, student_id: str, max_age_seconds: int = 300) -> bool:
-        """Checks if a response exists in Redis for the given student."""
+    def is_response_fresh(self, student_id: str) -> bool:
+        """
+        Checks if a response exists in Redis for the given student.
+        This is much simpler and more reliable now.
+        """
         key = self._get_key(student_id)
-        # redis.exists() is the direct equivalent of checking if the key is present
+        # redis.exists() returns the number of keys that exist (0 or 1 in this case).
         return self.redis.exists(key) > 0
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