Update app.py

app.py

@@ -6,7 +6,11 @@ import threading
 NUM_BACKEND_SERVERS = 3
 
 # Initialize backend servers (pipelines) and availability flags
-backend_servers = [pipeline("question-answering", model="google-bert/bert-large-uncased-whole-word-masking-finetuned-squad") for _ in range(NUM_BACKEND_SERVERS)]
+backend_servers = [
+    pipeline("question-answering", model="google-bert/bert-large-uncased-whole-word-masking-finetuned-squad"),
+    pipeline("question-answering", model="deepset/roberta-base-squad2"),
+    pipeline("question-answering", model="Intel/dynamic_tinybert")
+] * (NUM_BACKEND_SERVERS // 3)
 backend_locks = [threading.Lock() for _ in range(NUM_BACKEND_SERVERS)]
 
 # Function to select a backend server (pipeline) based on availability