Volcano 安装和使用¶
Volcano 是 CNCF 下首个基于 Kubernetes 的容器批处理计算平台，专注于高性能计算场景。 它填补了 Kubernetes 在机器学习、大数据、科学计算等领域缺失的功能，为这些高性能工作负载提供了必要的支持。
Volcano 与主流计算框架无缝对接，如 Spark、TensorFlow、PyTorch 等，并支持异构设备的混合调度，包括 CPU 和 GPU。
本文介绍如何安装和使用 Volcano。
安装 Volcano¶
-
在 集群详情 -> Helm 应用 -> Helm 模板 中找到 Volcano 并安装。
-
检查并确认 Volcano 是否安装完成，即 volcano-admission、volcano-controllers、volcano-scheduler 组件是否正常运行。
Volcano 使用场景¶
使用 Volcano 调度 Job 资源¶
- Volcano 是单独的调度器，在创建工作负载的时候指定调度器的名称（schedulerName: volcano）。
- volcanoJob 资源是 Volcano 对 Job 的扩展，它将 job 拆分成更小的工作单位 task，这些 task 之间可以相互作用。
使用示例：
apiVersion: batch.volcano.sh/v1alpha1
kind: Job
metadata:
name: nginx-job
spec:
minAvailable: 2
schedulerName: volcano
tasks:
- replicas: 1
name: master
template:
spec:
containers:
- image: docker.m.daocloud.io/library/nginx:latest
name: mpimaster
- replicas: 2
name: worker
template:
spec:
containers:
- image: docker.m.daocloud.io/library/nginx:latest
name: mpiworker
并行计算 mpi¶
使用示例：
apiVersion: batch.volcano.sh/v1alpha1
kind: Job
metadata:
name: lm-mpi-job
labels:
"volcano.sh/job-type": "MPI" # (1)!
spec:
minAvailable: 4
schedulerName: volcano
plugins:
ssh: [] # (2)!
svc: [] # (3)!
policies:
- event: PodEvicted
action: RestartJob
tasks:
- replicas: 1
name: mpimaster
policies:
- event: TaskCompleted
action: CompleteJob
template:
spec:
containers:
- command:
- /bin/sh
- -c
- |
MPI_HOST=`cat /etc/volcano/mpiworker.host | tr "\n" ","`;
mkdir -p /var/run/sshd; /usr/sbin/sshd;
mpiexec --allow-run-as-root --host ${MPI_HOST} -np 3 mpi_hello_world;
image: docker.m.daocloud.io/volcanosh/example-mpi:0.0.1
name: mpimaster
ports:
- containerPort: 22
name: mpijob-port
workingDir: /home
resources:
requests:
cpu: "500m"
limits:
cpu: "500m"
restartPolicy: OnFailure
imagePullSecrets:
- name: default-secret
- replicas: 3
name: mpiworker
template:
spec:
containers:
- command:
- /bin/sh
- -c
- |
mkdir -p /var/run/sshd; /usr/sbin/sshd -D;
image: docker.m.daocloud.io/volcanosh/example-mpi:0.0.1
name: mpiworker
ports:
- containerPort: 22
name: mpijob-port
workingDir: /home
resources:
requests:
cpu: "1000m"
limits:
cpu: "1000m"
restartPolicy: OnFailure
imagePullSecrets:
- name: default-secret
- Volcano 原生支持 MPI 的调度作业
- Volcano 插件，master 和 worker 之间可以免密登录
- master 和 worker 之间通过网络访问，自动创建 headless svc 资源
Volcano 支持 TensorFlow¶
使用示例：
apiVersion: batch.volcano.sh/v1alpha1
kind: Job
metadata:
name: tensorflow-benchmark
labels:
"volcano.sh/job-type": "Tensorflow" # (1)!
spec:
minAvailable: 3
schedulerName: volcano
plugins:
env: []
svc: []
policies:
- event: PodEvicted
action: RestartJob
tasks:
- replicas: 1
name: ps
template:
spec:
imagePullSecrets:
- name: default-secret
containers:
- command:
- sh
- -c
- |
PS_HOST=`cat /etc/volcano/ps.host | sed 's/$/&:2222/g' | tr "\n" ","`;
WORKER_HOST=`cat /etc/volcano/worker.host | sed 's/$/&:2222/g' | tr "\n" ","`;
python tf_cnn_benchmarks.py --batch_size=32 --model=resnet50 --variable_update=parameter_server --flush_stdout=true --num_gpus=1 --local_parameter_device=cpu --device=cpu --data_format=NHWC --job_name=ps --task_index=${VK_TASK_INDEX} --ps_hosts=${PS_HOST} --worker_hosts=${WORKER_HOST}
image: docker.m.daocloud.io/volcanosh/example-tf:0.0.1
name: tensorflow
ports:
- containerPort: 2222
name: tfjob-port
resources:
requests:
cpu: "1000m"
memory: "2048Mi"
limits:
cpu: "1000m"
memory: "2048Mi"
workingDir: /opt/tf-benchmarks/scripts/tf_cnn_benchmarks
restartPolicy: OnFailure
- replicas: 2
name: worker
policies:
- event: TaskCompleted
action: CompleteJob
template:
spec:
imagePullSecrets:
- name: default-secret
containers:
- command:
- sh
- -c
- |
PS_HOST=`cat /etc/volcano/ps.host | sed 's/$/&:2222/g' | tr "\n" ","`;
WORKER_HOST=`cat /etc/volcano/worker.host | sed 's/$/&:2222/g' | tr "\n" ","`;
python tf_cnn_benchmarks.py --batch_size=32 --model=resnet50 --variable_update=parameter_server --flush_stdout=true --num_gpus=1 --local_parameter_device=cpu --device=cpu --data_format=NHWC --job_name=worker --task_index=${VK_TASK_INDEX} --ps_hosts=${PS_HOST} --worker_hosts=${WORKER_HOST}
image: docker.m.daocloud.io/volcanosh/example-tf:0.0.1
name: tensorflow
ports:
- containerPort: 2222
name: tfjob-port
resources:
requests:
cpu: "2000m"
memory: "2048Mi"
limits:
cpu: "2000m"
memory: "4096Mi"
workingDir: /opt/tf-benchmarks/scripts/tf_cnn_benchmarks
restartPolicy: OnFailure
- Volcano 原生支持 tensorflow 的调度作业
如果您想了解 Volcano 更多功能特性和使用场景，可以参考 Volcano 介绍。