[Bugfix] Fix MessageQueue connect_ip for cross-node data parallelism (#35429)

Signed-off-by: Lu Fang <fanglu@fb.com>
Co-authored-by: Lu Fang <30275821+houseroad@users.noreply.github.com>

vllm/v1/executor/multiproc_executor.py

@@ -44,6 +44,7 @@ from vllm.logger import init_logger
 from vllm.tracing import instrument, maybe_init_worker_tracer
 from vllm.utils.network_utils import (
     get_distributed_init_method,
+    get_ip,
     get_loopback_ip,
     get_open_port,
 )
@@ -128,11 +129,23 @@ class MultiprocExecutor(Executor):
             # For leader node within each dp rank,
             # each dp will have its own leader multiproc executor.
             max_chunk_bytes = envs.VLLM_MQ_MAX_CHUNK_BYTES_MB * 1024 * 1024
+            mq_connect_ip = get_ip()
+            logger.info(
+                "DP group leader: node_rank=%d, node_rank_within_dp=%d, "
+                "master_addr=%s, mq_connect_ip=%s (local), "
+                "world_size=%d, local_world_size=%d",
+                self.parallel_config.node_rank,
+                self.parallel_config.node_rank_within_dp,
+                self.parallel_config.master_addr,
+                mq_connect_ip,
+                self.world_size,
+                self.local_world_size,
+            )
             self.rpc_broadcast_mq = MessageQueue(
                 self.world_size,
                 self.local_world_size,
                 max_chunk_bytes=max_chunk_bytes,
-                connect_ip=self.parallel_config.master_addr,
+                connect_ip=mq_connect_ip,
             )
             scheduler_output_handle = self.rpc_broadcast_mq.export_handle()
         # Create workers