Add Ray actor support for scheduler process management (DP=1) (#17684)

Co-authored-by: Cursor <cursoragent@cursor.com>

python/sglang/launch_server.py

@@ -28,6 +28,16 @@ def run_server(server_args):
         from sglang.srt.entrypoints.grpc_server import serve_grpc
 
         asyncio.run(serve_grpc(server_args))
+    elif server_args.use_ray:
+        try:
+            from sglang.srt.ray.http_server import launch_server
+        except ImportError:
+            raise ImportError(
+                "Ray is required for --use-ray mode. "
+                "Install it with: pip install 'sglang[ray]'"
+            )
+
+        launch_server(server_args)
     else:
         # Default mode: HTTP mode.
         from sglang.srt.entrypoints.http_server import launch_server