diff --git a/verl/single_controller/ray/base.py b/verl/single_controller/ray/base.py
index 0ec0c97e623..8f0ca14c3e3 100644
--- a/verl/single_controller/ray/base.py
+++ b/verl/single_controller/ray/base.py
@@ -87,7 +87,7 @@ def __init__(
         self,
         process_on_nodes: Optional[List[int]] = None,
         use_gpu: bool = True,
-        name_prefix: str = "",
+        name_prefix: str = None,
         max_colocate_count: int = 10,
         detached=False,
         accelerator_type: Optional[str] = None,
@@ -95,7 +95,7 @@ def __init__(
         super().__init__(process_on_nodes, max_colocate_count)
         self.use_gpu = use_gpu
         # print(f"in RayProcessDispatchConfiguration: name_prefix = {name_prefix}")
-        self.name_prefix = name_prefix
+        self.name_prefix = get_random_string(length=6) if name_prefix is None else name_prefix
         self.pgs = None
         self.detached = detached
         self.accelerator_type = accelerator_type