Machine learning inference using Amazon Inferentia

To create a cluster with Inf1 Amazon EC2 instance nodes

1. 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.

   Note

   You can't use IAM roles for service accounts with TensorFlow Serving.

   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

   Note

   Note the value of the following line of the output. It's used in a later (optional) step.

   [9]  adding identity "arn:aws-cn: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 Amazon 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.

2. 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

1. 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-cn:iam::aws:policy/AmazonS3ReadOnlyAccess \
       --role-name eksctl-inferentia-nodegroup-ng-in-NodeInstanceRole-FI7HIYS3BS09

2. 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.

   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

3. Deploy the model.

   kubectl apply -f rn50_deployment.yaml

4. 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

5. Create a Kubernetes service for your TensorFlow model Serving application.

   kubectl apply -f rn50_service.yaml

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

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

2. 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))

3. 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)]]