[router] add base_gpu_id server args & merged radix tree python reference (#2115)

python/sglang/srt/managers/data_parallel_controller.py

@@ -156,7 +156,7 @@ class DataParallelController:
         )
         for tp_rank in tp_rank_range:
             reader, writer = mp.Pipe(duplex=False)
-            gpu_id = base_gpu_id + tp_rank % tp_size_per_node
+            gpu_id = server_args.base_gpu_id + base_gpu_id + tp_rank % tp_size_per_node
             proc = mp.Process(
                 target=run_scheduler_process,
                 args=(server_args, port_args, gpu_id, tp_rank, dp_rank, writer),

python/sglang/srt/managers/scheduler.py

@@ -1380,6 +1380,10 @@ def run_scheduler_process(
     dp_rank: Optional[int],
     pipe_writer,
 ):
+    # [For Router] if env var "DP_RANK" exist, set dp_rank to the value of the env var
+    if dp_rank is None:
+        dp_rank = int(os.getenv("DP_RANK", -1))
+
     if dp_rank is None:
         configure_logger(server_args, prefix=f" TP{tp_rank}")
     else: