From 7df4a236f46d4525327e13974c1f4e3c871ca630 Mon Sep 17 00:00:00 2001
From: CJYLZS <691086891@qq.com>
Date: Wed, 18 Mar 2026 09:34:43 +0800
Subject: [PATCH] fix(router): address greptile review on least-busy
 tie-breaking

- Remove misleading `in ("1", "2")` assertion in stale-entry test; "2"
  can never be returned since "1" is always the unique minimum after
  filtering the stale "0" entry
- Replace unreachable `return random.choice(healthy_deployments)` fallback
  with explicit ValueError guards; the old fallback was dead code after
  the healthy-ID filter ensured min_deployment_ids is always non-empty,
  and still raised IndexError on an empty list anyway

Made-with: Cursor
---
 litellm/router_strategy/least_busy.py              | 14 ++++++++------
 .../router_strategy/test_least_busy.py             |  1 -
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/litellm/router_strategy/least_busy.py b/litellm/router_strategy/least_busy.py
index 74b142a1d8b..e4487854f3b 100644
--- a/litellm/router_strategy/least_busy.py
+++ b/litellm/router_strategy/least_busy.py
@@ -215,13 +215,15 @@ class LeastBusyLoggingHandler(CustomLogger):
             elif v == min_traffic:
                 min_deployment_ids.append(k)
 
-        if min_deployment_ids:
-            chosen_id = random.choice(min_deployment_ids)
-            for m in healthy_deployments:
-                if m["model_info"]["id"] == chosen_id:
-                    return m
+        if not min_deployment_ids:
+            raise ValueError("No healthy deployments available")
 
-        return random.choice(healthy_deployments)
+        chosen_id = random.choice(min_deployment_ids)
+        for m in healthy_deployments:
+            if m["model_info"]["id"] == chosen_id:
+                return m
+
+        raise ValueError(f"Chosen deployment id {chosen_id!r} not found in healthy_deployments")
 
     def get_available_deployments(
         self,
diff --git a/tests/test_litellm/router_strategy/test_least_busy.py b/tests/test_litellm/router_strategy/test_least_busy.py
index a1d678e35c9..f434f6a6f77 100644
--- a/tests/test_litellm/router_strategy/test_least_busy.py
+++ b/tests/test_litellm/router_strategy/test_least_busy.py
@@ -89,7 +89,6 @@ class TestLeastBusyTieBreaking:
                 healthy_deployments=healthy,
                 all_deployments=dict(counts_with_stale),
             )
-            assert chosen["model_info"]["id"] in ("1", "2")
             assert chosen["model_info"]["id"] == "1"