Remove MQ multi-node tests (#38934)

Signed-off-by: Jeffrey Wang <jeffreywang@anyscale.com>

.buildkite/test_areas/distributed.yaml

@@ -224,20 +224,6 @@ steps:
   commands:
     - ./.buildkite/scripts/run-multi-node-test.sh /vllm-workspace/tests 2 2 $IMAGE_TAG "VLLM_TEST_SAME_HOST=0 torchrun --nnodes 2 --nproc-per-node=2 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_same_node.py | grep 'Same node test passed' && NUM_NODES=2 torchrun --nnodes 2 --nproc-per-node=2 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_node_count.py | grep 'Node count test passed' && python3 ../examples/offline_inference/data_parallel.py -dp=2 -tp=1 --dp-num-nodes=2 --dp-node-rank=0 --dp-master-addr=192.168.10.10 --dp-master-port=12345 --enforce-eager --trust-remote-code && VLLM_MULTI_NODE=1 pytest -v -s distributed/test_multi_node_assignment.py && VLLM_MULTI_NODE=1 pytest -v -s distributed/test_pipeline_parallel.py" "VLLM_TEST_SAME_HOST=0 torchrun --nnodes 2 --nproc-per-node=2 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_same_node.py | grep 'Same node test passed' && NUM_NODES=2 torchrun --nnodes 2 --nproc-per-node=2 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_node_count.py | grep 'Node count test passed' && python3 ../examples/offline_inference/data_parallel.py -dp=2 -tp=1 --dp-num-nodes=2 --dp-node-rank=1 --dp-master-addr=192.168.10.10 --dp-master-port=12345 --enforce-eager --trust-remote-code"
 
-- label: MessageQueue TCP Multi-Node (2 GPUs)
-  timeout_in_minutes: 10
-  working_dir: "/vllm-workspace/tests"
-  num_devices: 1
-  num_nodes: 2
-  no_plugin: true
-  optional: true
-  source_file_dependencies:
-  - vllm/distributed/device_communicators/shm_broadcast.py
-  - vllm/distributed/parallel_state.py
-  - tests/distributed/test_mq_tcp_multinode.py
-  commands:
-    - ./.buildkite/scripts/run-multi-node-test.sh /vllm-workspace/tests 2 1 $IMAGE_TAG "torchrun --nnodes 2 --nproc-per-node=1 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_mq_tcp_multinode.py" "torchrun --nnodes 2 --nproc-per-node=1 --rdzv_backend=c10d --rdzv_endpoint=192.168.10.10 distributed/test_mq_tcp_multinode.py"
-
 - label: Distributed NixlConnector PD accuracy (4 GPUs)
   timeout_in_minutes: 30
   working_dir: "/vllm-workspace/tests"

tests/distributed/test_mq_tcp_multinode.py

-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
-"""
-Multi-node integration test for MessageQueue TCP fallback.
-
-Verifies that when writer and readers span separate nodes (Docker containers
-with isolated /dev/shm), `create_from_process_group` correctly detects
-cross-node ranks via `in_the_same_node_as()` and falls back to ZMQ TCP
-transport — and that data actually arrives.
-"""
-
-import numpy as np
-import torch.distributed as dist
-
-from vllm.distributed.device_communicators.shm_broadcast import MessageQueue
-from vllm.distributed.parallel_state import in_the_same_node_as
-
-
-def main():
-    dist.init_process_group(backend="gloo")
-
-    rank = dist.get_rank()
-    world_size = dist.get_world_size()
-    assert world_size >= 2, (
-        f"Need at least 2 ranks across nodes, got world_size={world_size}"
-    )
-
-    # Verify that in_the_same_node_as detects cross-node correctly
-    status = in_the_same_node_as(dist.group.WORLD, source_rank=0)
-    local_count = sum(status)
-    print(
-        f"[Rank {rank}] in_the_same_node_as(source=0): {status}  "
-        f"(local={local_count}/{world_size})"
-    )
-    # With 2 Docker containers (1 proc each), rank 0 and rank 1
-    # should be on different nodes.
-    assert local_count < world_size, (
-        f"Expected cross-node ranks but all {world_size} ranks appear local."
-    )
-
-    # Create MessageQueue
-    writer_rank = 0
-    mq = MessageQueue.create_from_process_group(
-        dist.group.WORLD,
-        max_chunk_bytes=1024 * 1024,  # 1 MiB
-        max_chunks=10,
-        writer_rank=writer_rank,
-    )
-
-    # Verify the transport path selection
-    if rank == writer_rank:
-        print(
-            f"[Rank {rank}] Writer: n_local_reader={mq.n_local_reader}, "
-            f"n_remote_reader={mq.n_remote_reader}"
-        )
-        assert mq.n_remote_reader > 0, (
-            "Writer should have at least 1 remote (TCP) reader in a multi-node setup."
-        )
-    else:
-        if status[rank]:
-            assert mq._is_local_reader, (
-                f"Rank {rank} is on the same node as writer but is not a local reader."
-            )
-            print(f"[Rank {rank}] Reader: local (shared memory)")
-        else:
-            assert mq._is_remote_reader, (
-                f"Rank {rank} is on a different node but is not a remote (TCP) reader."
-            )
-            print(f"[Rank {rank}] Reader: remote (TCP)")
-
-    # Test data transfer: simple objects
-    dist.barrier()
-    if rank == writer_rank:
-        mq.enqueue("hello_from_node0")
-    else:
-        msg = mq.dequeue(timeout=10)
-        assert msg == "hello_from_node0"
-    dist.barrier()
-    print(f"[Rank {rank}] Simple object test passed")
-
-    # Test data transfer: numpy arrays
-    np.random.seed(42)
-    arrays = [
-        np.random.randint(0, 100, size=np.random.randint(100, 5000)) for _ in range(100)
-    ]
-
-    dist.barrier()
-    if rank == writer_rank:
-        for arr in arrays:
-            mq.enqueue(arr)
-    else:
-        for i, expected in enumerate(arrays):
-            received = mq.dequeue(timeout=10)
-            assert np.array_equal(expected, received), (
-                f"Array mismatch at index {i}: "
-                f"expected shape {expected.shape}, got shape {received.shape}"
-            )
-    dist.barrier()
-    print(f"[Rank {rank}] Numpy array test passed")
-
-    # Test data transfer: large payload (> max_chunk_bytes)
-    dist.barrier()
-    big_array = np.zeros(200_000, dtype=np.int64)  # ~1.6 MiB > 1 MiB chunk
-    if rank == writer_rank:
-        mq.enqueue(big_array)
-    else:
-        received = mq.dequeue(timeout=10)
-        assert np.array_equal(big_array, received)
-    dist.barrier()
-    print(f"[Rank {rank}] Large payload test passed")
-
-    # Done -- cleanup
-    dist.barrier()
-    print(f"[Rank {rank}] All MessageQueue TCP multi-node tests passed!")
-    dist.destroy_process_group()
-
-
-if __name__ == "__main__":
-    main()