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Predict on an InferenceService with a saved model on PVC

This doc shows how to store a model in PVC and create InferenceService with a saved model on PVC.

Create PV and PVC

Refer to the document to create Persistent Volume (PV) and Persistent Volume Claim (PVC), the PVC will be used to store model. This document uses local PV.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: task-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/home/ubuntu/mnt/data"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: task-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
kubectl apply -f pv-and-pvc.yaml

Copy model to PV

Run pod model-store-pod and login into container model-store.

apiVersion: v1
kind: Pod
metadata:
  name: model-store-pod
spec:
  volumes:
    - name: model-store
      persistentVolumeClaim:
        claimName: task-pv-claim
  containers:
    - name: model-store
      image: ubuntu
      command: [ "sleep" ]
      args: [ "infinity" ]
      volumeMounts:
        - mountPath: "/pv"
          name: model-store
      resources:
        limits:
          memory: "1Gi"
          cpu: "1"
kubectl apply -f pv-model-store.yaml

kubectl exec -it model-store-pod -- bash

In different terminal, copy the model from local into PV.

kubectl cp model.joblib model-store-pod:/pv/model.joblib -c model-store

Deploy InferenceService with models on PVC

Update the ${PVC_NAME} to the created PVC name and create the InferenceService with the PVC storageUri.

apiVersion: "serving.kserve.io/v1beta1"
kind: "InferenceService"
metadata:
  name: "sklearn-pvc"
spec:
  predictor:
    sklearn:
      storageUri: "pvc://${PVC_NAME}/model.joblib"
kubectl apply -f sklearn-pvc.yaml

Run a prediction

Now, the ingress can be accessed at ${INGRESS_HOST}:${INGRESS_PORT} or follow this instruction to find out the ingress IP and port.

SERVICE_HOSTNAME=$(kubectl get inferenceservice sklearn-pvc -o jsonpath='{.status.url}' | cut -d "/" -f 3)

MODEL_NAME=sklearn-pvc
INPUT_PATH=@./input.json
curl -v -H "Host: ${SERVICE_HOSTNAME}" http://${INGRESS_HOST}:${INGRESS_PORT}/v1/models/$MODEL_NAME:predict -d $INPUT_PATH

Expected Output

*   Trying 127.0.0.1:8080...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8080 (#0)
> POST /v1/models/sklearn-pvc:predict HTTP/1.1
> Host: sklearn-pvc.default.example.com
> User-Agent: curl/7.68.0
> Accept: */*
> Content-Length: 84
> Content-Type: application/x-www-form-urlencoded
> 
* upload completely sent off: 84 out of 84 bytes
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< content-length: 23
< content-type: application/json; charset=UTF-8
< date: Mon, 20 Sep 2021 04:55:50 GMT
< server: istio-envoy
< x-envoy-upstream-service-time: 6
< 
* Connection #0 to host localhost left intact
{"predictions": [1, 1]}