xc-llm-ascend/docs/source/developer_guide/contribution/multi_node_test.md

# Multi Node Test

Multi-Node CI is designed to test distributed scenarios of very large models, eg: disaggregated_prefill multi DP across multi nodes and so on.

## How is works

The following picture shows the basic deployment view of the multi-node CI mechanism, It shows how the github action interact with [lws](https://lws.sigs.k8s.io/docs/overview/) (a kind of kubernetes crd resource)

![alt text](../../assets/deployment.png)

From the workflow perspective, we can see how the final test script is executed, The key point is that these two [lws.yaml and run.sh](https://github.com/vllm-project/vllm-ascend/tree/main/tests/e2e/nightly/multi_node/scripts), The former defines how our k8s cluster is pulled up, and the latter defines the entry script when the pod is started, Each node executes different logic according to the [LWS_WORKER_INDEX](https://lws.sigs.k8s.io/docs/reference/labels-annotations-and-environment-variables/) environment variable, so that multiple nodes can form a distributed cluster to perform tasks.

![alt text](../../assets/workflow.png)

## How to contribute

1. Upload custom weights

   If you need customized weights, for example, you quantized a w8a8 weight for DeepSeek-V3 and you want your weight to run on CI, Uploading weights to ModelScope's [vllm-ascend](https://www.modelscope.cn/organization/vllm-ascend) organization is welcome, If you do not have permission to upload, please contact @Potabk

2. Add config yaml

    As the entrypoint script [run.sh](https://github.com/vllm-project/vllm-ascend/blob/0bf3f21a987aede366ec4629ad0ffec8e32fe90d/tests/e2e/nightly/multi_node/scripts/run.sh#L106) shows, A k8s pod startup means traversing all *.yaml files in the [directory](https://github.com/vllm-project/vllm-ascend/tree/main/tests/e2e/nightly/multi_node/config/), reading and executing according to different configurations, so what we need to do is just add "yamls" like [DeepSeek-V3.yaml](https://github.com/vllm-project/vllm-ascend/blob/main/tests/e2e/nightly/multi_node/config/DeepSeek-V3.yaml).

    Suppose you have **2 nodes** running a 1P1D setup (1 Prefillers + 1 Decoder):

    you may add a config file looks like:

    ```yaml
    test_name: "test DeepSeek-V3 disaggregated_prefill"
    # the model being tested
    model: "vllm-ascend/DeepSeek-V3-W8A8"
    # how large the cluster is
    num_nodes: 2
    npu_per_node: 16
    # All env vars you need should add it here
    env_common:
    VLLM_USE_MODELSCOPE: true
    OMP_PROC_BIND: false
    OMP_NUM_THREADS: 100
    HCCL_BUFFSIZE: 1024
    SERVER_PORT: 8080
    disaggregated_prefill:
    enabled: true
    # node index(a list) which meet all the conditions:
    #  - prefiller
    #  - no headless(have api server)
    prefiller_host_index: [0]
    # node index(a list) which meet all the conditions:
    #  - decoder
    decoder_host_index: [1]

    # Add each node's vllm serve cli command just like you run locally
    # Add each node's individual envs like follow
    deployment:
    -
        envs:
            # fill with envs like: <key>:<value>
        server_cmd: >
            vllm serve ...
    -
        envs:
            # fill with envs like: <key>:<value>
        server_cmd: >
            vllm serve ...
    benchmarks:
    perf:
        # fill with performance test kwargs
    acc:
        # fill with accuracy test kwargs
    ```

3. Add the case to nightly workflow
currently, the multi-node test workflow defined in the [nightly_test_a3.yaml](https://github.com/vllm-project/vllm-ascend/blob/main/.github/workflows/nightly_test_a3.yaml)

   ```yaml
    multi-node-tests:
        name: multi-node
        if: always() && (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch')
        strategy:
        fail-fast: false
        max-parallel: 1
        matrix:
            test_config:
            - name: multi-node-deepseek-pd
                config_file_path: DeepSeek-V3.yaml
                size: 2
            - name: multi-node-qwen3-dp
                config_file_path: Qwen3-235B-A22B.yaml
                size: 2
            - name: multi-node-qwenw8a8-2node
                config_file_path: Qwen3-235B-W8A8.yaml
                size: 2
            - name: multi-node-qwenw8a8-2node-eplb
                config_file_path: Qwen3-235B-W8A8-EPLB.yaml
                size: 2
        uses: ./.github/workflows/_e2e_nightly_multi_node.yaml
        with:
        soc_version: a3
        runner: linux-aarch64-a3-0
        image: 'swr.cn-southwest-2.myhuaweicloud.com/base_image/ascend-ci/vllm-ascend:nightly-a3'
        replicas: 1
        size: ${{ matrix.test_config.size }}
        config_file_path: ${{ matrix.test_config.config_file_path }}
        secrets:
        KUBECONFIG_B64: ${{ secrets.KUBECONFIG_B64 }}
   ```
  
The matrix above defines all the parameters required to add a multi-machine use case, The parameters worth paying attention to (I mean if you are adding a new use case) are size and the path to the yaml configuration file. The former defines the number of nodes required for your use case, and the latter defines the path to the configuration file you have completed in step 2.

## Run Multi-Node tests locally

### 1. Use kubernetes

This section assumes that you already have a [Kubernetes](https://kubernetes.io/docs/setup/) NPU cluster environment locally. then you can easily start our test with one click.

- Step 1. Install LWS CRD resources

    See <https://lws.sigs.k8s.io/docs/installation/> Which can be used as a reference

- Step 2. Deploy the following yaml file `lws.yaml` as what you want

    ```yaml
    apiVersion: leaderworkerset.x-k8s.io/v1
    kind: LeaderWorkerSet
    metadata:
    name: test-server
    namespace: vllm-project
    spec:
    replicas: 1
    leaderWorkerTemplate:
        size: 2
        restartPolicy: None
        leaderTemplate:
        metadata:
            labels:
            role: leader
        spec:
            containers:
            - name: vllm-leader
                imagePullPolicy: Always
                image: swr.cn-southwest-2.myhuaweicloud.com/base_image/ascend-ci/vllm-ascend:nightly-a3
                env:
                - name: CONFIG_YAML_PATH
                    value: DeepSeek-V3.yaml
                - name: WORKSPACE
                    value: "/vllm-workspace"
                - name: FAIL_TAG
                    value: FAIL_TAG
                command:
                - sh
                - -c
                - |
                    bash /vllm-workspace/vllm-ascend/tests/e2e/nightly/multi_node/scripts/run.sh
                resources:
                limits:
                    huawei.com/ascend-1980: 16
                    memory: 512Gi
                    ephemeral-storage: 100Gi
                requests:
                    huawei.com/ascend-1980: 16
                    memory: 512Gi
                    ephemeral-storage: 100Gi
                    cpu: 125
                ports:
                - containerPort: 8080
                # readinessProbe:
                #   tcpSocket:
                #     port: 8080
                #   initialDelaySeconds: 15
                #   periodSeconds: 10
                volumeMounts:
                - mountPath: /root/.cache
                    name: shared-volume
                - mountPath: /usr/local/Ascend/driver/tools
                    name: driver-tools
                - mountPath: /dev/shm
                    name: dshm
            volumes:
            - name: dshm
            emptyDir:
                medium: Memory
                sizeLimit: 15Gi
            - name: shared-volume
            persistentVolumeClaim:
                claimName: nv-action-vllm-benchmarks-v2
            - name: driver-tools
            hostPath:
                path: /usr/local/Ascend/driver/tools
        workerTemplate:
        spec:
            containers:
            - name: vllm-worker
                imagePullPolicy: Always
                image: swr.cn-southwest-2.myhuaweicloud.com/base_image/ascend-ci/vllm-ascend:nightly-a3
                env:
                - name: CONFIG_YAML_PATH
                    value: DeepSeek-V3.yaml
                - name: WORKSPACE
                    value: "/vllm-workspace"
                - name: FAIL_TAG
                    value: FAIL_TAG
                command:
                - sh
                - -c
                - |
                    bash /vllm-workspace/vllm-ascend/tests/e2e/nightly/multi_node/scripts/run.sh
                resources:
                limits:
                    huawei.com/ascend-1980: 16
                    memory: 512Gi
                    ephemeral-storage: 100Gi
                requests:
                    huawei.com/ascend-1980: 16
                    ephemeral-storage: 100Gi
                    cpu: 125
                volumeMounts:
                - mountPath: /root/.cache
                    name: shared-volume
                - mountPath: /usr/local/Ascend/driver/tools
                    name: driver-tools
                - mountPath: /dev/shm
                    name: dshm
            volumes:
            - name: dshm
            emptyDir:
                medium: Memory
                sizeLimit: 15Gi
            - name: shared-volume
            persistentVolumeClaim:
                claimName: nv-action-vllm-benchmarks-v2
            - name: driver-tools
            hostPath:
                path: /usr/local/Ascend/driver/tools
    ---
    apiVersion: v1
    kind: Service
    metadata:
    name: vllm-leader
    namespace: vllm-project
    spec:
    ports:
        - name: http
        port: 8080
        protocol: TCP
        targetPort: 8080
    selector:
        leaderworkerset.sigs.k8s.io/name: vllm
        role: leader
    type: ClusterIP
    ```

    ```bash
    kubectl apply -f lws.yaml
    ```

    Verify the status of the pods:

    ```bash
    kubectl get pods -n vllm-project
    ```

    Should get an output similar to this:

    ```bash
    NAME       READY   STATUS    RESTARTS   AGE
    vllm-0     1/1     Running   0          2s
    vllm-0-1   1/1     Running   0          2s
    ```

    Verify that the distributed inference works:

    ```bash
    kubectl logs -f vllm-0 -n vllm-project
    ```

    Should get something similar to this:

    ```shell
    INFO 12-30 11:00:57 [__init__.py:43] Available plugins for group vllm.platform_plugins:
    INFO 12-30 11:00:57 [__init__.py:45] - ascend -> vllm_ascend:register
    INFO 12-30 11:00:57 [__init__.py:48] All plugins in this group will be loaded. Set `VLLM_PLUGINS` to control which plugins to load.
    INFO 12-30 11:00:57 [__init__.py:217] Platform plugin ascend is activated
    INFO 12-30 11:00:57 [importing.py:68] Triton not installed or not compatible; certain GPU-related functions will not be available.
    ================================================================================================== test session starts ===================================================================================================
    platform linux -- Python 3.11.13, pytest-8.4.2, pluggy-1.6.0 -- /usr/local/python3.11.13/bin/python3
    cachedir: .pytest_cache
    rootdir: /vllm-workspace/vllm-ascend
    configfile: pyproject.toml
    plugins: cov-7.0.0, asyncio-1.3.0, mock-3.15.1, anyio-4.12.0
    asyncio: mode=Mode.STRICT, debug=False, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function
    collected 1 item

    tests/e2e/nightly/multi_node/scripts/test_multi_node.py::test_multi_node [2025-12-30 11:01:01] INFO multi_node_config.py:294: Loading config yaml: tests/e2e/nightly/multi_node/config/DeepSeek-V3.yaml
    [2025-12-30 11:01:01] INFO multi_node_config.py:348: Resolving cluster IPs via DNS...
    [2025-12-30 11:01:01] INFO multi_node_config.py:212: Node 0 envs: {'VLLM_USE_MODELSCOPE': 'True', 'OMP_PROC_BIND': 'False', 'OMP_NUM_THREADS': '100', 'HCCL_BUFFSIZE': '1024', 'SERVER_PORT': '8080', 'NUMEXPR_MAX_THREADS': '128', 'DISAGGREGATED_PREFILL_PROXY_SCRIPT': 'examples/disaggregated_prefill_v1/load_balance_proxy_server_example.py', 'HCCL_IF_IP': '10.0.0.102', 'HCCL_SOCKET_IFNAME': 'eth0', 'GLOO_SOCKET_IFNAME': 'eth0', 'TP_SOCKET_IFNAME': 'eth0', 'LOCAL_IP': '10.0.0.102', 'NIC_NAME': 'eth0', 'MASTER_IP': '10.0.0.102'}
    [2025-12-30 11:01:01] INFO multi_node_config.py:159: Launching proxy: python examples/disaggregated_prefill_v1/load_balance_proxy_server_example.py --host 10.0.0.102 --port 6000 --prefiller-hosts 10.0.0.102 --prefiller-ports 8080 --decoder-hosts 10.0.0.138 --decoder-ports 8080
    [2025-12-30 11:01:01] INFO conftest.py:107: Starting server with command: vllm serve vllm-ascend/DeepSeek-V3-W8A8 --host 0.0.0.0 --port 8080 --data-parallel-size 2 --data-parallel-size-local 2 --tensor-parallel-size 8 --seed 1024 --enforce-eager --enable-expert-parallel --max-num-seqs 16 --max-model-len 8192 --max-num-batched-tokens 8192 --quantization ascend --trust-remote-code --no-enable-prefix-caching --gpu-memory-utilization 0.9 --kv-transfer-config {"kv_connector": "MooncakeConnectorV1", "kv_role": "kv_producer", "kv_port": "30000", "engine_id": "0", "kv_connector_extra_config": {
            "prefill": {
                    "dp_size": 2,
                    "tp_size": 8
            },
            "decode": {
                    "dp_size": 2,
                    "tp_size": 8
            }
        }
    }
    ```

### 2. Test without kubernetes

Since our script is Kubernetes-friendly, we need to actively pass in some cluster information if you don't have a Kubernetes environment.

- Step 1. Add cluster_hosts to config yamls

    Modify on every cluster host, commands just like [DeepSeek-V3.yaml](https://github.com/vllm-project/vllm-ascend/blob/e760aae1df7814073a4180172385505c1ec0fd83/tests/e2e/nightly/multi_node/config/DeepSeek-V3.yaml#L25) after the configure item `num_nodes` , for example:
    `cluster_hosts: ["xxx.xxx.xxx.188", "xxx.xxx.xxx.212"]`

- Step 2. Install develop environment
    - Install vllm-ascend develop packages on every cluster host

      ``` bash
      cd /vllm-workspace/vllm-ascend
      python3 -m pip install -r requirements-dev.txt
      ```

    - Install AISBench on the first host(leader node) in cluster_hosts

      ``` bash
      export AIS_BENCH_TAG="v3.0-20250930-master"
      export AIS_BENCH_URL="https://gitee.com/aisbench/benchmark.git"
      export BENCHMARK_HOME=/vllm-workspace/benchmark

      git clone -b ${AIS_BENCH_TAG} --depth 1 ${AIS_BENCH_URL} $BENCHMARK_HOME
      cd $BENCHMARK_HOME
      pip install -e . -r requirements/api.txt -r requirements/extra.txt
        ```

- Step 3. Running test locally

    Run the script on **each node separately**

    ``` bash
    export WORKSPACE=/vllm-workspace # Change it to your path locally
    export CONFIG_YAML_PATH="DeepSeek-V3.yaml" # Replace with the config case you added
    cd $WORKSPACE/vllm-ascend
    bash tests/e2e/nightly/multi_node/scripts/run.sh
    ```