Starting an Amazon Rekognition Custom Labels model

In the Start or stop model section do the following:

In the Use your model section do the following:

Change the value of project-version-arn to the ARN of the model that you want to start. Change the value of --min-inference-units to the number of inference units that you want to use. Optionally, change --max-inference-units to the maximum number of inference units that Amazon Rekognition Custom Labels can use to automatically scale the model.

aws rekognition start-project-version  --project-version-arn model_arn \
   --min-inference-units minimum number of units \
   --max-inference-units maximum number of units \
   --profile custom-labels-access 
 

Supply the following command line parameters:

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0

"""
Purpose
Shows how to start running an Amazon Lookout for Vision model.
"""

import argparse
import logging
import boto3
from botocore.exceptions import ClientError

logger = logging.getLogger(__name__)


def get_model_status(rek_client, project_arn, model_arn):
    """
    Gets the current status of an Amazon Rekognition Custom Labels model
    :param rek_client: The Amazon Rekognition Custom Labels Boto3 client.
    :param project_name:  The name of the project that you want to use.
    :param model_arn:  The name of the model that you want the status for.
    :return: The model status
    """

    logger.info("Getting status for %s.", model_arn)

    # Extract the model version from the model arn.
    version_name = (model_arn.split("version/", 1)[1]).rpartition('/')[0]

    models = rek_client.describe_project_versions(ProjectArn=project_arn,
                                                  VersionNames=[version_name])

    for model in models['ProjectVersionDescriptions']:

        logger.info("Status: %s", model['StatusMessage'])
        return model["Status"]

    error_message = f"Model {model_arn} not found."
    logger.exception(error_message)
    raise Exception(error_message)


def start_model(rek_client, project_arn, model_arn, min_inference_units, max_inference_units=None):
    """
    Starts the hosting of an Amazon Rekognition Custom Labels model.
    :param rek_client: The Amazon Rekognition Custom Labels Boto3 client.
    :param project_name:  The name of the project that contains the
    model that you want to start hosting.
    :param min_inference_units: The number of inference units to use for hosting.
    :param max_inference_units: The number of inference units to use for auto-scaling
    the model. If not supplied, auto-scaling does not happen.
    """

    try:
        # Start the model
        logger.info(f"Starting model: {model_arn}. Please wait....")

        if max_inference_units is None:
            rek_client.start_project_version(ProjectVersionArn=model_arn,
                                             MinInferenceUnits=int(min_inference_units))
        else:
            rek_client.start_project_version(ProjectVersionArn=model_arn,
                                             MinInferenceUnits=int(
                                                 min_inference_units),
                                             MaxInferenceUnits=int(max_inference_units))

        # Wait for the model to be in the running state
        version_name = (model_arn.split("version/", 1)[1]).rpartition('/')[0]
        project_version_running_waiter = rek_client.get_waiter(
            'project_version_running')
        project_version_running_waiter.wait(
            ProjectArn=project_arn, VersionNames=[version_name])

        # Get the running status
        return get_model_status(rek_client, project_arn, model_arn)

    except ClientError as err:
        logger.exception("Client error: Problem starting model: %s", err)
        raise


def add_arguments(parser):
    """
    Adds command line arguments to the parser.
    :param parser: The command line parser.
    """

    parser.add_argument(
        "project_arn", help="The ARN of the project that contains that the model you want to start."
    )
    parser.add_argument(
        "model_arn", help="The ARN of the model that you want to start."
    )
    parser.add_argument(
        "min_inference_units", help="The minimum number of inference units to use."
    )
    parser.add_argument(
        "--max_inference_units",  help="The maximum number of inference units to use for auto-scaling the model.", required=False
    )


def main():

    logging.basicConfig(level=logging.INFO,
                        format="%(levelname)s: %(message)s")

    try:

        # Get command line arguments.
        parser = argparse.ArgumentParser(usage=argparse.SUPPRESS)
        add_arguments(parser)
        args = parser.parse_args()

        # Start the model.
        session = boto3.Session(profile_name='custom-labels-access')
        rekognition_client = session.client("rekognition")
        
        status = start_model(rekognition_client,
                             args.project_arn, args.model_arn,
                             args.min_inference_units,
                             args.max_inference_units)

        print(f"Finished starting model: {args.model_arn}")
        print(f"Status: {status}")

    except ClientError as err:
        error_message = f"Client error: Problem starting model: {err}"
        logger.exception(error_message)
        print(error_message)

    except Exception as err:
        error_message = f"Problem starting model:{err}"
        logger.exception(error_message)
        print(error_message)


if __name__ == "__main__":
    main()

Supply the following command line parameters:

/*
   Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
   SPDX-License-Identifier: Apache-2.0
*/
package com.example.rekognition;

import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.rekognition.RekognitionClient;
import software.amazon.awssdk.services.rekognition.model.DescribeProjectVersionsRequest;
import software.amazon.awssdk.services.rekognition.model.DescribeProjectVersionsResponse;
import software.amazon.awssdk.services.rekognition.model.ProjectVersionDescription;
import software.amazon.awssdk.services.rekognition.model.ProjectVersionStatus;
import software.amazon.awssdk.services.rekognition.model.RekognitionException;
import software.amazon.awssdk.services.rekognition.model.StartProjectVersionRequest;
import software.amazon.awssdk.services.rekognition.model.StartProjectVersionResponse;
import software.amazon.awssdk.services.rekognition.waiters.RekognitionWaiter;

import java.util.Optional;
import java.util.logging.Level;
import java.util.logging.Logger;

public class StartModel {

    public static final Logger logger = Logger.getLogger(StartModel.class.getName());
    
    
    
    public static int findForwardSlash(String modelArn, int n) {

        int start = modelArn.indexOf('/');
        while (start >= 0 && n > 1) {
            start = modelArn.indexOf('/', start + 1);
            n -= 1;
        }
        return start;

    }

    public static void startMyModel(RekognitionClient rekClient, String projectArn, String modelArn,
            Integer minInferenceUnits, Integer maxInferenceUnits
            ) throws Exception, RekognitionException {

        try {
            
            logger.log(Level.INFO, "Starting model: {0}", modelArn);
            
            StartProjectVersionRequest startProjectVersionRequest = null;
            
            if (maxInferenceUnits == null) {
                startProjectVersionRequest = StartProjectVersionRequest.builder()
                    .projectVersionArn(modelArn)
                    .minInferenceUnits(minInferenceUnits)
                    .build();
            }
            else {
                startProjectVersionRequest = StartProjectVersionRequest.builder()
                        .projectVersionArn(modelArn)
                        .minInferenceUnits(minInferenceUnits)
                        .maxInferenceUnits(maxInferenceUnits)
                        .build();
                
            }

            StartProjectVersionResponse response = rekClient.startProjectVersion(startProjectVersionRequest);

            logger.log(Level.INFO, "Status: {0}", response.statusAsString() );
            
            
            // Get the model version

            int start = findForwardSlash(modelArn, 3) + 1;
            int end = findForwardSlash(modelArn, 4);

            String versionName = modelArn.substring(start, end);


            // wait until model starts

            DescribeProjectVersionsRequest describeProjectVersionsRequest = DescribeProjectVersionsRequest.builder()
                    .versionNames(versionName)
                    .projectArn(projectArn)
                    .build();

            RekognitionWaiter waiter = rekClient.waiter();

            WaiterResponse<DescribeProjectVersionsResponse> waiterResponse = waiter
                    .waitUntilProjectVersionRunning(describeProjectVersionsRequest);

            Optional<DescribeProjectVersionsResponse> optionalResponse = waiterResponse.matched().response();

            DescribeProjectVersionsResponse describeProjectVersionsResponse = optionalResponse.get();

            for (ProjectVersionDescription projectVersionDescription : describeProjectVersionsResponse
                    .projectVersionDescriptions()) {
                if(projectVersionDescription.status() == ProjectVersionStatus.RUNNING) {
                    logger.log(Level.INFO, "Model is running" );
                 
                }
                else {
                    String error = "Model training failed: " + projectVersionDescription.statusAsString() + " "
                            + projectVersionDescription.statusMessage() + " " + modelArn;
                    logger.log(Level.SEVERE, error);
                    throw new Exception(error);
                }
                
            }


        } catch (RekognitionException e) {
            logger.log(Level.SEVERE, "Could not start model: {0}", e.getMessage());
            throw e;
        }

    }

    public static void main(String[] args) {

        String modelArn = null;
        String projectArn = null;
        Integer minInferenceUnits = null;
        Integer maxInferenceUnits = null;
        



        final String USAGE = "\n" + "Usage: " + "<project_name> <version_name> <min_inference_units> <max_inference_units>\n\n" + "Where:\n"
                + "   project_arn - The ARN of the project that contains the model that you want to start. \n\n"
                + "   model_arn - The ARN of the model version that you want to start.\n\n"
                + "   min_inference_units - The number of inference units to start the model with.\n\n"
                + "   max_inference_units - The maximum number of inference units that Custom Labels can use to "
                + "   automatically scale the model. If the value is null, automatic scaling doesn't happen.\n\n";

        if (args.length < 3  || args.length >4) {
            System.out.println(USAGE);
            System.exit(1);
        }

        projectArn = args[0];
        modelArn = args[1];
        minInferenceUnits=Integer.parseInt(args[2]);
        
        if (args.length == 4) {
            maxInferenceUnits = Integer.parseInt(args[3]);
        }
  
        try {


            // Get the Rekognition client.
            RekognitionClient rekClient = RekognitionClient.builder()
            .credentialsProvider(ProfileCredentialsProvider.create("custom-labels-access"))
            .region(Region.US_WEST_2)
            .build();

            // Start the model.
            startMyModel(rekClient, projectArn, modelArn, minInferenceUnits, maxInferenceUnits);
            

            System.out.println(String.format("Model started: %s", modelArn));

            rekClient.close();

        } catch (RekognitionException rekError) {
            logger.log(Level.SEVERE, "Rekognition client error: {0}", rekError.getMessage());
            System.exit(1);
        } catch (Exception rekError) {
            logger.log(Level.SEVERE, "Error: {0}", rekError.getMessage());
            System.exit(1);
        }

        

    }

}