From 971948b846994819c50cb5c5f04a54822635e303 Mon Sep 17 00:00:00 2001
From: Huy Do <huydhn@gmail.com>
Date: Sat, 26 Jul 2025 20:35:22 -0700
Subject: [PATCH] Handle non-serializable objects in vllm bench (#21665)

---
 vllm/benchmarks/utils.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/vllm/benchmarks/utils.py b/vllm/benchmarks/utils.py
index f0bb99326ab40..5f95fdcc75829 100644
--- a/vllm/benchmarks/utils.py
+++ b/vllm/benchmarks/utils.py
@@ -67,4 +67,9 @@ class InfEncoder(json.JSONEncoder):
 
 def write_to_json(filename: str, records: list) -> None:
     with open(filename, "w") as f:
-        json.dump(records, f, cls=InfEncoder)
+        json.dump(
+            records,
+            f,
+            cls=InfEncoder,
+            default=lambda o: f"<{type(o).__name__} is not JSON serializable>",
+        )