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Thursday, January 23, 2025

Optimizing AI Workloads with NVIDA GPUs, Time Slicing, and Karpenter (Half 2)


Introduction: Overcoming GPU Administration Challenges  

In Half 1 of this weblog sequence, we explored the challenges of internet hosting giant language fashions (LLMs) on CPU-based workloads inside an EKS cluster. We mentioned the inefficiencies related to utilizing CPUs for such duties, primarily because of the giant mannequin sizes and slower inference speeds. The introduction of GPU assets provided a major efficiency enhance, however it additionally introduced in regards to the want for environment friendly administration of those high-cost assets. 

On this second half, we’ll delve deeper into the right way to optimize GPU utilization for these workloads. We are going to cowl the next key areas: 

  • NVIDIA System Plugin Setup: This part will clarify the significance of the NVIDIA gadget plugin for Kubernetes, detailing its position in useful resource discovery, allocation, and isolation. 
  • Time Slicing: We’ll focus on how time slicing permits a number of processes to share GPU assets successfully, guaranteeing most utilization. 
  • Node Autoscaling with Karpenter: This part will describe how Karpenter dynamically manages node scaling based mostly on real-time demand, optimizing useful resource utilization and decreasing prices. 

Challenges Addressed 

  1. Environment friendly GPU Administration: Guaranteeing GPUs are totally utilized to justify their excessive value. 
  2. Concurrency Dealing with: Permitting a number of workloads to share GPU assets successfully. 
  3. Dynamic Scaling: Routinely adjusting the variety of nodes based mostly on workload calls for. 

 Part 1: Introduction to NVIDIA System Plugin 

 The NVIDIA gadget plugin for Kubernetes is a element that simplifies the administration and utilization of NVIDIA GPUs in Kubernetes clusters. It permits Kubernetes to acknowledge and allocate GPU assets to pods, enabling GPU-accelerated workloads. 

Why We Want the NVIDIA System Plugin 

  • Useful resource Discovery: Routinely detects NVIDIA GPU assets on every node.
  • Useful resource Allocation: Manages the distribution of GPU assets to pods based mostly on their requests.
  • Isolation: Ensures safe and environment friendly utilization of GPU assets amongst totally different pods. 

 The NVIDIA gadget plugin simplifies GPU administration in Kubernetes clusters. It automates the set up of the NVIDIA driver, container toolkit, and CUDA, guaranteeing that GPU assets can be found for workloads with out requiring handbook setup. 

  • NVIDIA Driver: Required for nvidia-smi and primary GPU operations. Interfacing with the GPU {hardware}. The screenshot under shows the output of the nvidia-smi command, which exhibits key data similar to the motive force model, CUDA model, and detailed GPU configuration, confirming that the GPU is correctly configured and prepared to be used 

 

  • NVIDIA Container Toolkit: Required for utilizing GPUs with containerd. Under we are able to see the model of the container toolkit model and the standing of the service working on the occasion 
#Put in Model 
rpm -qa | grep -i nvidia-container-toolkit 
nvidia-container-toolkit-base-1.15.0-1.x86_64 
nvidia-container-toolkit-1.15.0-1.x86_64 
  • CUDA: Required for GPU-accelerated purposes and libraries. Under is the output of the nvcc command, exhibiting the model of CUDA put in on the system:
/usr/native/cuda/bin/nvcc --model 
nvcc: NVIDIA (R) Cuda compiler driver 
Copyright (c) 2005-2023 NVIDIA Company 
Constructed on Tue_Aug_15_22:02:13_PDT_2023 
Cuda compilation instruments, launch 12.2, V12.2.140 
Construct cuda_12.2.r12.2/compiler.33191640_0 

Setting Up the NVIDIA System Plugin 

To make sure the DaemonSet runs completely on GPU-based cases, we label the node with the important thing “nvidia.com/gpu” and the worth “true”. That is achieved utilizing Node affinity, Node selector and Taints and Tolerations.

Allow us to now delve into every of those elements intimately. 

  • Node Affinity:  Node affinity permits to schedule pod on the nodes based mostly on the node labels requiredDuringSchedulingIgnoredDuringExecution: The scheduler can not schedule the Pod except the rule is met, and the secret’s “nvidia.com/gpu” and operator is “in,” and the values is “true.” 
affinity: 
    nodeAffinity: 
        requiredDuringSchedulingIgnoredDuringExecution: 
            nodeSelectorTerms: 
                - matchExpressions: 
                    - key: function.node.kubernetes.io/pci-10de.current 
                      operator: In 
                      values: 
                        - "true" 
                - matchExpressions: 
                    - key: function.node.kubernetes.io/cpu-mannequin.vendor_id 
                      operator: In 
                      values: 
                      - NVIDIA 
                - matchExpressions: 
                    - key: nvidia.com/gpu 
                      operator: In 
                      values: 
                    - "true" 
  • Node selector:   Node selector is the best advice kind for node choice constraints nvidia.com/gpu: “true” 
  • Taints and Tolerations: Tolerations are added to the Daemon Set to make sure it may be scheduled on the contaminated GPU nodes(nvidia.com/gpu=true:Noschedule).
kubectl taint node ip-10-20-23-199.us-west-1.compute.inner nvidia.com/gpu=true:Noschedule 
kubectl describe node ip-10-20-23-199.us-west-1.compute.inner | grep -i taint 
Taints: nvidia.com/gpu=true:NoSchedule 

tolerations: 
  - impact: NoSchedule 
    key: nvidia.com/gpu 
    operator: Exists 

After implementing the node labeling, affinity, node selector, and taints/tolerations, we are able to make sure the Daemon Set runs completely on GPU-based cases. We are able to confirm the deployment of the NVIDIA gadget plugin utilizing the next command: 

kubectl get ds -n kube-system 
NAME                                      DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE  NODE SELECTOR                                     AGE 

nvidia-gadget-plugin                      1         1         1       1            1          nvidia.com/gpu=true                               75d 
nvidia-gadget-plugin-mps-management-daemon   0         0         0       0            0          nvidia.com/gpu=true,nvidia.com/mps.succesful=true   75d 

However the problem right here is GPUs are so costly and wish to verify the utmost utilization of GPU’s and allow us to discover extra on GPU Concurrency. 

GPU Concurrency:   

Refers back to the potential to execute a number of duties or threads concurrently on a GPU 

  • Single Course of: In a single course of setup, just one software or container makes use of the GPU at a time. This method is simple however might result in underutilization of the GPU assets if the appliance doesn’t totally load the GPU. 
  • Multi-Course of Service (MPS): NVIDIA’s Multi-Course of Service (MPS) permits a number of CUDA purposes to share a single GPU concurrently, enhancing GPU utilization and decreasing the overhead of context switching. 
  • Time slicing:  Time slicing includes dividing the GPU time between totally different processes in different phrases a number of course of takes activates GPU’s (Spherical Robin context Switching) 
  • Multi Occasion GPU(MIG): MIG is a function accessible on NVIDIA A100 GPUs that permits a single GPU to be partitioned into a number of smaller, remoted cases, every behaving like a separate GPU. 
  • Virtualization: GPU virtualization permits a single bodily GPU to be shared amongst a number of digital machines (VMs) or containers, offering every with a digital GPU. 

 Part 2: Implementing Time Slicing for GPUs 

Time-slicing within the context of NVIDIA GPUs and Kubernetes refers to sharing a bodily GPU amongst a number of containers or pods in a Kubernetes cluster. The know-how includes partitioning the GPU’s processing time into smaller intervals and allocating these intervals to totally different containers or pods. 

  • Time Slice Allocation: The GPU scheduler allocates time slices to every vGPU configured on the bodily GPU. 
  • Preemption and Context Switching: On the finish of a vGPU’s time slice, the GPU scheduler preempts its execution, saves its context, and switches to the following vGPU’s context. 
  • Context Switching: The GPU scheduler ensures clean context switching between vGPUs, minimizing overhead, and guaranteeing environment friendly use of GPU assets. 
  • Job Completion: Processes inside containers full their GPU-accelerated duties inside their allotted time slices. 
  • Useful resource Administration and Monitoring
  • Useful resource Launch: As duties full, GPU assets are launched again to Kubernetes for reallocation to different pods or containers 

Why We Want Time Slicing 

  • Price Effectivity: Ensures high-cost GPUs aren’t underutilized. 
  • Concurrency: Permits a number of purposes to make use of the GPU concurrently. 

 Configuration Instance for Time Slicing  

Allow us to apply the time slicing config utilizing config map as proven under. Right here replicas: 3 specifies the variety of replicas for GPU assets that implies that GPU useful resource may be sliced into 3 sharing cases 

apiVersion: v1 
type: ConfigMap 
metadata: 
  identify: nvidia-gadget-plugin 
  namespace: kube-system 
knowledge: 
  any: |- 
    model: v1 
    flags: 
      migStrategy: none 
    sharing: 
      timeSlicing: 
        assets: 
        - identify: nvidia.com/gpu 
          replicas: 3 
#We are able to confirm the GPU assets accessible in your nodes utilizing the next command:     
kubectl get nodes -o json | jq -r '.objects[] | choose(.standing.capability."nvidia.com/gpu" != null) 
| {identify: .metadata.identify, capability: .standing.capability}' 

  "identify": "ip-10-20-23-199.us-west-1.compute.inner", 
  "capability": { 
    "cpu": "4", 
    "ephemeral-storage": "104845292Ki", 
    "hugepages-1Gi": "0", 
    "hugepages-2Mi": "0", 
    "reminiscence": "16069060Ki", 
    "nvidia.com/gpu": "3", 
    "pods": "110" 
  } 

#The above output exhibits that the node ip-10-20-23-199.us-west-1. compute.inner has 3 digital GPUs accessible. 
#We are able to request GPU assets of their pod specs by setting useful resource limits 
assets: 
      limits: 
        cpu: "1" 
        reminiscence: 2G 
        nvidia.com/gpu: "1" 
      requests: 
        cpu: "1" 
        reminiscence: 2G 
        nvidia.com/gpu: "1" 

In our case we are able to be capable to host 3 pods in a single node ip-10-20-23-199.us-west-1. compute. Inside and due to time slicing these 3 pods can use 3 digital GPU’s as under 

GPUs have been shared nearly among the many pods, and we are able to see the PIDS assigned for every of the processes under. 

Now we optimized GPU on the pod degree, allow us to now give attention to optimizing GPU assets on the node degree. We are able to obtain this through the use of a cluster autoscaling resolution referred to as Karpenter. That is significantly essential as the educational labs might not all the time have a continuing load or consumer exercise, and GPUs are extraordinarily costly. By leveraging Karpenter, we are able to dynamically scale GPU nodes up or down based mostly on demand, guaranteeing cost-efficiency and optimum useful resource utilization. 

Part 3: Node Autoscaling with Karpenter 

Karpenter is an open-source node lifecycle administration for Kubernetes. It automates provisioning and deprovisioning of nodes based mostly on the scheduling wants of pods, permitting environment friendly scaling and price optimization 

  • Dynamic Node Provisioning: Routinely scales nodes based mostly on demand. 
  • Optimizes Useful resource Utilization: Matches node capability with workload wants. 
  • Reduces Operational Prices: Minimizes pointless useful resource bills. 
  • Improves Cluster Effectivity: Enhances total efficiency and responsiveness. 

Why Use Karpenter for Dynamic Scaling 

  • Dynamic Scaling: Routinely adjusts node rely based mostly on workload calls for. 
  • Price Optimization: Ensures assets are solely provisioned when wanted, decreasing bills. 
  • Environment friendly Useful resource Administration: Tracks pods unable to be scheduled attributable to lack of assets, evaluations their necessities, provisions nodes to accommodate them, schedules the pods, and decommissions nodes when redundant. 

Putting in Karpenter: 

 #Set up Karpenter utilizing HELM:
helm improve --set up karpenter oci://public.ecr.aws/karpenter/karpenter --model "${KARPENTER_VERSION}" 
--namespace "${KARPENTER_NAMESPACE}" --create-namespace   --set "settings.clusterName=${CLUSTER_NAME}"    
--set "settings.interruptionQueue=${CLUSTER_NAME}"    --set controller.assets.requests.cpu=1    
--set controller.assets.requests.reminiscence=1Gi    --set controller.assets.limits.cpu=1    
--set controller.assets.limits.reminiscence=1Gi 

#Confirm Karpenter Set up: 
kubectl get pod -n kube-system | grep -i karpenter 
karpenter-7df6c54cc-rsv8s             1/1     Working   2 (10d in the past)   53d 
karpenter-7df6c54cc-zrl9n             1/1     Working   0             53d 

 Configuring Karpenter with NodePools and NodeClasses:  

Karpenter may be configured with NodePools and NodeClasses to automate the provisioning and scaling of nodes based mostly on the particular wants of your workloads 

  • Karpenter NodePool: Nodepool is a customized useful resource that defines a set of nodes with shared specs and constraints in a Kubernetes cluster. Karpenter makes use of NodePools to dynamically handle and scale node assets based mostly on the necessities of working workloads 
apiVersion: karpenter.sh/v1beta1 
type: NodePool 
metadata: 
  identify: g4-nodepool 
spec: 
  template: 
    metadata: 
      labels: 
        nvidia.com/gpu: "true" 
    spec: 
      taints: 
        - impact: NoSchedule 
          key: nvidia.com/gpu 
          worth: "true" 
      necessities: 
        - key: kubernetes.io/arch 
          operator: In 
          values: ["amd64"] 
        - key: kubernetes.io/os 
          operator: In 
          values: ["linux"] 
        - key: karpenter.sh/capability-sort 
          operator: In 
          values: ["on-demand"] 
        - key: node.kubernetes.io/occasion-sort 
          operator: In 
          values: ["g4dn.xlarge" ] 
      nodeClassRef: 
        apiVersion: karpenter.k8s.aws/v1beta1 
        type: EC2NodeClass 
        identify: g4-nodeclass 
  limits: 
    cpu: 1000 
  disruption: 
    expireAfter: 120m 
    consolidationPolicy: WhenUnderutilized 
  • NodeClasses are configurations that outline the traits and parameters for the nodes that Karpenter can provision in a Kubernetes cluster. A NodeClass specifies the underlying infrastructure particulars for nodes, similar to occasion sorts, launch template configurations and particular cloud supplier settings. 

Observe: The userData part comprises scripts to bootstrap the EC2 occasion, together with pulling a TensorFlow GPU Docker picture and configuring the occasion to hitch the Kubernetes cluster. 

apiVersion: karpenter.k8s.aws/v1beta1 
type: EC2NodeClass 
metadata: 
  identify: g4-nodeclass 
spec: 
  amiFamily: AL2 
  launchTemplate: 
    identify: "ack_nodegroup_template_new" 
    model: "7"  
  position: "KarpenterNodeRole" 
  subnetSelectorTerms: 
    - tags: 
        karpenter.sh/discovery: "nextgen-learninglab" 
  securityGroupSelectorTerms: 
    - tags: 
        karpenter.sh/discovery: "nextgen-learninglab"     
  blockDeviceMappings: 
    - deviceName: /dev/xvda 
      ebs: 
        volumeSize: 100Gi 
        volumeType: gp3 
        iops: 10000 
        encrypted: true 
        deleteOnTermination: true 
        throughput: 125 
  tags: 
    Identify: Learninglab-Staging-Auto-GPU-Node 
  userData: | 
        MIME-Model: 1.0 
        Content material-Kind: multipart/blended; boundary="//" 
        --// 
        Content material-Kind: textual content/x-shellscript; charset="us-ascii" 
        set -ex 
        sudo ctr -n=k8s.io picture pull docker.io/tensorflow/tensorflow:2.12.0-gpu 
        --// 
        Content material-Kind: textual content/x-shellscript; charset="us-ascii" 
        B64_CLUSTER_CA=" " 
        API_SERVER_URL="" 
        /and so on/eks/bootstrap.sh nextgen-learninglab-eks --kubelet-further-args '--node-labels=eks.amazonaws.com/capacityType=ON_DEMAND 
--pod-max-pids=32768 --max-pods=110' -- b64-cluster-ca $B64_CLUSTER_CA --apiserver-endpoint $API_SERVER_URL --use-max-pods false 
         --// 
        Content material-Kind: textual content/x-shellscript; charset="us-ascii" 
        KUBELET_CONFIG=/and so on/kubernetes/kubelet/kubelet-config.json 
        echo "$(jq ".podPidsLimit=32768" $KUBELET_CONFIG)" > $KUBELET_CONFIG 
        --// 
        Content material-Kind: textual content/x-shellscript; charset="us-ascii" 
        systemctl cease kubelet 
        systemctl daemon-reload 
        systemctl begin kubelet
        --//--

On this situation, every node (e.g., ip-10-20-23-199.us-west-1.compute.inner) can accommodate as much as three pods. If the deployment is scaled so as to add one other pod, the assets will probably be inadequate, inflicting the brand new pod to stay in a pending state.  

 

Karpenter displays these Un schedulable pods and assesses their useful resource necessities to behave accordingly. There will probably be nodeclaim which claims the node from the nodepool and Karpenter thus provision a node based mostly on the requirement. 

 

 Conclusion: Environment friendly GPU Useful resource Administration in Kubernetes 

With the rising demand for GPU-accelerated workloads in Kubernetes, managing GPU assets successfully is important. The mixture of NVIDIA System Plugin, time slicing, and Karpenter supplies a robust method to handle, optimize, and scale GPU assets in a Kubernetes cluster, delivering excessive efficiency with environment friendly useful resource utilization. This resolution has been applied to host pilot GPU-enabled Studying Labs on developer.cisco.com/studying, offering GPU-powered studying experiences.

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