Use AWS Inferentia instances with Amazon EKS for Machine Learning

Create a cluster with Inf1 Amazon EC2 instance nodes. You can replace inf1.2xlarge with any Inf1 instance type. The eksctl utility detects that you are launching a node group with an Inf1 instance type and will start your nodes using one of the Amazon EKS optimized accelerated Amazon Linux AMIs.

eksctl create cluster \
    --name inferentia \
    --region region-code \
    --nodegroup-name ng-inf1 \
    --node-type inf1.2xlarge \
    --nodes 2 \
    --nodes-min 1 \
    --nodes-max 4 \
    --ssh-access \
    --ssh-public-key your-key \
    --with-oidc

[9]  adding identity "arn:aws:iam::111122223333:role/eksctl-inferentia-nodegroup-ng-in-NodeInstanceRole-FI7HIYS3BS09" to auth ConfigMap

When launching a node group with Inf1 instances, eksctl automatically installs the AWS Neuron Kubernetes device plugin. This plugin advertises Neuron devices as a system resource to the Kubernetes scheduler, which can be requested by a container. In addition to the default Amazon EKS node IAM policies, the Amazon S3 read only access policy is added so that the sample application, covered in a later step, can load a trained model from Amazon S3.

Make sure that all Pods have started correctly.

kubectl get pods -n kube-system

Abbreviated output:

NAME                                   READY   STATUS    RESTARTS   AGE
[...]
neuron-device-plugin-daemonset-6djhp   1/1     Running   0          5m
neuron-device-plugin-daemonset-hwjsj   1/1     Running   0          5m

Add the AmazonS3ReadOnlyAccess IAM policy to the node instance role that was created in step 1 of Create a cluster. This is necessary so that the sample application can load a trained model from Amazon S3.

aws iam attach-role-policy \
    --policy-arn arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess \
    --role-name eksctl-inferentia-nodegroup-ng-in-NodeInstanceRole-FI7HIYS3BS09

Create a file named rn50_deployment.yaml with the following contents. Update the region-code and model path to match your desired settings. The model name is for identification purposes when a client makes a request to the TensorFlow server. This example uses a model name to match a sample ResNet50 client script that will be used in a later step for sending prediction requests.

aws ecr list-images --repository-name neuron-rtd --registry-id 790709498068 --region us-west-2

kind: Deployment
apiVersion: apps/v1
metadata:
  name: eks-neuron-test
  labels:
    app: eks-neuron-test
    role: master
spec:
  replicas: 2
  selector:
    matchLabels:
      app: eks-neuron-test
      role: master
  template:
    metadata:
      labels:
        app: eks-neuron-test
        role: master
    spec:
      containers:
        - name: eks-neuron-test
          image: 763104351884.dkr.ecr.us-east-1.amazonaws.com/tensorflow-inference-neuron:1.15.4-neuron-py37-ubuntu18.04
          command:
            - /usr/local/bin/entrypoint.sh
          args:
            - --port=8500
            - --rest_api_port=9000
            - --model_name=resnet50_neuron
            - --model_base_path=s3://${your-bucket-of-models}/resnet50_neuron/
          ports:
            - containerPort: 8500
            - containerPort: 9000
          imagePullPolicy: IfNotPresent
          env:
            - name: AWS_REGION
              value: "us-east-1"
            - name: S3_USE_HTTPS
              value: "1"
            - name: S3_VERIFY_SSL
              value: "0"
            - name: S3_ENDPOINT
              value: s3.us-east-1.amazonaws.com
            - name: AWS_LOG_LEVEL
              value: "3"
          resources:
            limits:
              cpu: 4
              memory: 4Gi
              aws.amazon.com/neuron: 1
            requests:
              cpu: "1"
              memory: 1Gi
          securityContext:
            capabilities:
              add:
                - IPC_LOCK

Deploy the model.

kubectl apply -f rn50_deployment.yaml

Create a file named rn50_service.yaml with the following contents. The HTTP and gRPC ports are opened for accepting prediction requests.

kind: Service
apiVersion: v1
metadata:
  name: eks-neuron-test
  labels:
    app: eks-neuron-test
spec:
  type: ClusterIP
  ports:
    - name: http-tf-serving
      port: 8500
      targetPort: 8500
    - name: grpc-tf-serving
      port: 9000
      targetPort: 9000
  selector:
    app: eks-neuron-test
    role: master

Create a Kubernetes service for your TensorFlow model Serving application.

kubectl apply -f rn50_service.yaml

To test locally, forward the gRPC port to the eks-neuron-test service.

kubectl port-forward service/eks-neuron-test 8500:8500 &

Create a Python script called tensorflow-model-server-infer.py with the following content. This script runs inference via gRPC, which is service framework.

import numpy as np
   import grpc
   import tensorflow as tf
   from tensorflow.keras.preprocessing import image
   from tensorflow.keras.applications.resnet50 import preprocess_input
   from tensorflow_serving.apis import predict_pb2
   from tensorflow_serving.apis import prediction_service_pb2_grpc
   from tensorflow.keras.applications.resnet50 import decode_predictions

   if __name__ == '__main__':
       channel = grpc.insecure_channel('localhost:8500')
       stub = prediction_service_pb2_grpc.PredictionServiceStub(channel)
       img_file = tf.keras.utils.get_file(
           "./kitten_small.jpg",
           "https://raw.githubusercontent.com/awslabs/mxnet-model-server/master/docs/images/kitten_small.jpg")
       img = image.load_img(img_file, target_size=(224, 224))
       img_array = preprocess_input(image.img_to_array(img)[None, ...])
       request = predict_pb2.PredictRequest()
       request.model_spec.name = 'resnet50_inf1'
       request.inputs['input'].CopyFrom(
           tf.make_tensor_proto(img_array, shape=img_array.shape))
       result = stub.Predict(request)
       prediction = tf.make_ndarray(result.outputs['output'])
       print(decode_predictions(prediction))

Run the script to submit predictions to your service.

python3 tensorflow-model-server-infer.py

An example output is as follows.

[[(u'n02123045', u'tabby', 0.68817204), (u'n02127052', u'lynx', 0.12701613), (u'n02123159', u'tiger_cat', 0.08736559), (u'n02124075', u'Egyptian_cat', 0.063844085), (u'n02128757', u'snow_leopard', 0.009240591)]]