fix(router.py): handle initial scenario for tpm/rpm routing

litellm/router.py

@@ -1606,7 +1606,12 @@ class Router:
             self.routing_strategy == "usage-based-routing"
             and self.lowesttpm_logger is not None
         ):
-            return self.lowesttpm_logger.get_available_deployments(model_group=model)
+            min_deployment = self.lowesttpm_logger.get_available_deployments(
+                model_group=model
+            )
+            if min_deployment is None:
+                min_deployment = random.choice(healthy_deployments)
+            return min_deployment
 
         raise ValueError("No models available.")
 

litellm/router_strategy/lowest_tpm_rpm.py

@@ -136,6 +136,9 @@ class LowestTPMLoggingHandler(CustomLogger):
         lowest_tpm = float("inf")
         deployment = None
 
+        if tpm_dict is None:  # base case
+            return
+
         for item, item_tpm in tpm_dict.items():
             ## get the item from model list
             _deployment = None

litellm/tests/test_least_busy_routing.py

@@ -128,6 +128,3 @@ def test_router_get_available_deployments():
     assert return_dict[1] == 10
     assert return_dict[2] == 54
     assert return_dict[3] == 100
-
-
-# test_router_get_available_deployments()