Kubernetes执行程序不会并行化Airflow中的子DAG执行

Question

我们从Airflow 1.10.0中的Celery Executor搬走了,因为执行有一些限制,现在我们正在使用KubernetesExecutor.

现在,即使我们subdag_operator直接更改代码,我们也无法并行化某些DAG中的所有任务:https://github.com/apache/incubator-airflow/blob/v1-10-stable/airflow/operators /subdag_operator.py#L38

我们的期望是通过这些修改和使用Kubernetes Executors,我们可以同时扇出所有任务的执行,但我们有相同的行为SequentialExecutor.

这是我们现在的行为:

我们希望使用同时执行所有这些KubernetesExecutor.

Answer 1

Airflow 中的 Kubernetes Executor 会将所有第一级任务转变为具有 Local Executor 的 Worker Pod。

这意味着您将让本地执行器来执行您的SubDagOperator.

为了在生成工作 Pod 后在 SubDagOperator 下运行任务，您需要指定parallelism工作 Pod 的配置。因此，如果您对工作 Pod 使用 YAML 格式，则需要将其编辑为类似以下内容。

apiVersion: v1
kind: Pod
metadata:
  name: dummy-name
spec:
  containers:
    - args: []
      command: []
      env:
        ###################################
        # This is the part you need to add
        ###################################
        - name: AIRFLOW__CORE__PARALLELISM
          value: 10
        ###################################
        - name: AIRFLOW__CORE__EXECUTOR
          value: LocalExecutor
        # Hard Coded Airflow Envs
        - name: AIRFLOW__CORE__FERNET_KEY
          valueFrom:
            secretKeyRef:
              name: RELEASE-NAME-fernet-key
              key: fernet-key
        - name: AIRFLOW__CORE__SQL_ALCHEMY_CONN
          valueFrom:
            secretKeyRef:
              name: RELEASE-NAME-airflow-metadata
              key: connection
        - name: AIRFLOW_CONN_AIRFLOW_DB
          valueFrom:
            secretKeyRef:
              name: RELEASE-NAME-airflow-metadata
              key: connection
      envFrom: []
      image: dummy_image
      imagePullPolicy: IfNotPresent
      name: base
      ports: []
      volumeMounts:
        - mountPath: "/opt/airflow/logs"
          name: airflow-logs
        - mountPath: /opt/airflow/dags
          name: airflow-dags
          readOnly: false
        - mountPath: /opt/airflow/dags
          name: airflow-dags
          readOnly: true
          subPath: repo/tests/dags
  hostNetwork: false
  restartPolicy: Never
  securityContext:
    runAsUser: 50000
  nodeSelector:
    {}
  affinity:
    {}
  tolerations:
    []
  serviceAccountName: 'RELEASE-NAME-worker-serviceaccount'
  volumes:
    - name: dags
      persistentVolumeClaim:
        claimName: RELEASE-NAME-dags
    - emptyDir: {}
      name: airflow-logs
    - configMap:
        name: RELEASE-NAME-airflow-config
      name: airflow-config
    - configMap:
        name: RELEASE-NAME-airflow-config
      name: airflow-local-settings

然后，SubDagOperator将按照parallelism指定并行运行任务。