Monitor deployed tensorflow models with Prometheus and Grafana

Table of Contents

1. Create and serve multiple models
2. Monitoring with Prometheus and Visualization with Grafana using docker-compose
3. Monitoring with Prometheus and Visualization with Grafana using Kubernetes
4. References

1 Create and serve multiple models

• We have to create and export the models that will be served. They will be stored in the models directory:

  python create_models.py

• We have to use the model server config file in models/models.config that specifies the locations of all exposed models:

  docker run -t --rm -p 8501:8501 -p 8500:8500\
      --name=serving \
      -v "$(pwd)/models/:/models/" \
      tensorflow/serving:2.11.0 \
      --model_config_file=/models/models.config \
      --allow_version_labels_for_unavailable_models=true \
      --model_config_file_poll_wait_seconds=60

  The --model_config_file_poll_wait_seconds=60 option means that the server polls model updates every 60s.

• Test the REST API:

  # model paths  
  # /v1/models/<model name>
  # /v1/models/<model name>/versions/<version number>
  # /v1/models/<model name>/labels/<version label>
  
  MODEL_PATH=half_plus_two/versions/1
  MODEL_PATH=half_plus_ten/labels/stable
  MODEL_PATH=half_plus_ten/labels/canary
  
  curl -X POST http://localhost:8501/v1/models/${MODEL_PATH}:predict \
      -H 'Content-type: application/json' \
      -d '{"signature_name": "serving_default", "instances": [{"x": [0, 1, 2]}]}'

2 Monitoring with Prometheus and Visualization with Grafana using docker-compose

• We will use the models/monitoring.config file that exposes a path that can be scraped by prometheus.

• In addition, we will use the prometheus_docker_compose.yml file. The scrape_configs.metrics_path matches the path exposed in models/monitoring.config.

• You can start the three services with docker-compose up.

• From docker-compose.yml you can see that:

  • to read metrics from /monitoring/prometheus/metrics we had to set --rest_api_port=8501 and --monitoring_config_file=/models/monitoring.config. You can verify that the metrics are exposed by visiting http://localhost:8501/monitoring/prometheus/metrics.

  • you should be able to access the Prometheus web UI through localhost:9090. You can also execute the query :tensorflow:serving:request_count and see what happens.

  • you should be able to access the Grafana WebUI through localhost:3000. The username and password are admin and admin, respectively. In the WebUI you can add a new datasource with the url http://prometheus:9090.

  • you can access the models with the same requests that you have used in the previous section.

• You can stop the three services with docker-compose down.

3 Monitoring with Prometheus and Visualization with Grafana using Kubernetes

• Tensorflow server

  • In the ideal case we have to mount a volume that contains the models into the pod running the tensorflow server. In order to make local testing easier we will just extend the tensorflow server image by adding to it the models:

    docker build -t tf-server:1.0.0 -f Dockerfile .
    
    # Create the server
    kubectl create namespace tfmodels
    helm install --namespace tfmodels tf-serving-chart helm/tf-serving

  • From the values.yaml in the helm chart for the tensorflow server you can see that:

    • we have enabled only the service component but not the ingress component. This has to be changed at some point.
    • we are pulling the locally stored tensorflow server image by setting pullPolicy: Never in tf-serving/values.yaml.

  • Besides values.yaml, Chart.yaml and templates/deplyment.yaml we have not changed the default template.

  • Since we have used a service of type LoadBalancer we can make API calls to the service in the same way as we did before.

• Prometheus

  • Launch prometheus with:

    kubectl create namespace monitoring
    helm install --namespace monitoring \
      -f prometheus_helm.yaml \
      prometheus-chart bitnami/kube-prometheus

    You should get a message telling you under which DNS from within the cluster Prometheus can be accessed.

    Prometheus can be accessed via port "9090" on the following DNS name from within your cluster:
    
      prometheus-chart-kube-prom-prometheus.monitoring.svc.cluster.local

    To access Prometheus from outside the cluster execute the following command:

    kubectl -n monitoring port-forward svc/prometheus-chart-kube-prom-prometheus 9090:9090
    # Browse to http://127.0.0.1:9090

  • To force Prometheus to monitor our service in tfmodels namespace, create a new ServiceMonitor component:

    kubectl apply -f helm/prometheus/servicemonitor.yaml

    The labels under spec.selector.matchLabels should match the labels of the service whose metrics endpoint we want to monitor (/monitoring/prometheus/metrics). In the prometheus UI under Status -> Targets you should see that a new serviceMonitor component was discovered.

• Grafana

  • Launch Grafana with:

    helm install --namespace monitoring \
      grafana-chart bitnami/grafana

    To access Grafana from outside the cluster execute the following command:

    kubectl -n monitoring port-forward svc/grafana-chart 8081:3000
    # Browse to http://127.0.0.1:8081 to access the service

  • You can add Prometheus as a datasource by using the previously obtained prometheus DNS name as a datasource URL: http://prometheus-chart-kube-prom-prometheus.monitoring.svc.cluster.local:9090.

• Remove all services:

  helm uninstall --namespace tfmodels tf-serving-chart
  helm uninstall --namespace monitoring prometheus-chart
  helm uninstall --namespace monitoring grafana-cahrt
  kubectl delete -f helm/prometheus/servicemonitor.yaml
  kubectl delete namespace tfmodels
  kubectl delete namespace monitoring

4 References

• https://github.com/thisisclement/Prometheus-TF-Serving
• https://github.com/bitnami/charts/tree/main/bitnami/mongodb
• https://www.youtube.com/watch?v=JGtJj_nAA2s
• https://www.youtube.com/watch?v=A-3RESuvjxo
• https://www.iguazio.com/blog/introduction-to-tf-serving/
• https://github.com/bentoml/Yatai
• https://medium.com/fourthline-tech/how-to-visualize-tensorflow-metrics-in-kibana-761268353ca3
• https://blog.krudewig-online.de/2021/02/22/Multicluster-Monitoring-with-Prometheus.html
• https://github.com/bitnami/charts/tree/main/bitnami/kube-prometheus
• https://docs.bitnami.com/tutorials/create-multi-cluster-monitoring-dashboard-thanos-grafana-prometheus/
• https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/