ECS Container Monitoring: Can See DataDog Agent Metrics but Not Main App Container Metrics

Environment:

• ECS on ARM64 Fargate
• Container Insights with Performance Monitoring enabled
• DataDog agent running as a sidecar container

Problem Description

I've enabled container monitoring with performance insights on my ECS cluster. In the CloudWatch Container Insights dashboard, I can correctly view:

• Cluster-level and service-level CPU and memory metrics
• Container-level CPU and memory metrics for the DataDog agent container
• Container-level Network TX, Network RX, Storage Read, and Storage Write metrics for ALL containers (including the main Kong container) However, I cannot see CPU and Memory metrics specifically for my main Kong container. The metrics simply don't appear in the Container Insights Performance monitoring dashboard, while they do appear for the DataDog agent container within the same task.

What I've Tried

• Confirmed that container insights is properly enabled on the cluster
• Verified that both containers (DataDog agent and main app) are in the same task definition
• Checked that the task execution role has proper CloudWatch permissions
• Confirmed that metrics are appearing at the cluster and service level

Task Definition:

{
  family: service,
  taskRoleArn: env_svc + '-task',
  executionRoleArn: env_svc + '-exec',
  networkMode: 'awsvpc',
  volumes: [],
  placementConstraints: [],
  requiresCompatibilities: [
    'FARGATE',
  ],
  cpu: '1024',
  memory: '2048',
  runtimePlatform: {
    operatingSystemFamily: 'LINUX',
    cpuArchitecture: "ARM64",
  },
  containerDefinitions: [
    {
      name: service,
      image: std.format('-%s:%s', [service, version]),
      environment: [
        {
          name: 'env',
          value: env,
        },
        {
          name: 'DD_ENV',
          value: env,
        },
        {
          name: 'DD_SERVICE',
          value: service,
        },
        {
          name: 'DD_VERSION',
          value: version,
        },
        {
          name: 'DD_TAGS',
          value: 'env:' + env,
        }
      ],
      essential: true,
      dockerLabels: {
        'com.datadoghq.ad.logs': std.format('[{ "source": "kong" , "service": "%s","version": "%s"}]', [service, version],),
        'com.datadoghq.ad.checks': '{ "kong": { "init_config": {}, "instances": [{ "openmetrics_endpoint": "http://127.0.0.1:8001/metrics"}]}}',
        'com.datadoghq.tags.env': env,
        'com.datadoghq.tags.service': service,
        'com.datadoghq.tags.version': version,
      },
      logConfiguration: {
        logDriver: 'awsfirelens',
        options: {
          dd_service: service,
          dd_source: 'kong',
          dd_tags: std.format('env:%s,service:%s,version:%s', [env, service, version]),
          Name: 'datadog',
        },
        secretOptions: [
          {
            name: 'apiKey',
            valueFrom: '/global/-',
          },
        ],
      },
      portMappings: [
        {
          name: 'app',  // required for service connect
          appProtocol: 'http',  // required for service connect
          containerPort: 8000,
          hostPort: 8000,
          protocol: 'tcp',
        },
        {
          containerPort: 8001,
          hostPort: 8001,
          protocol: 'tcp',
        },
      ],
      linuxParameters: {
        initProcessEnabled: true,
      },
      ulimits: [
        {
          name: 'nofile',
          softLimit: 8192,
          hardLimit: 1048576,
        },
      ],
    },
    {
      name: 'log_router',
      // https://github.com/aws/aws-for-fluent-bit#using-the-stable-tag
      image: '0123456789.dkr.ecr.eu-west-1.amazonaws.com/aws-for-fluent-bit:stable',
      firelensConfiguration: {
        type: 'fluentbit',
        options: {
          'config-file-type': 'file',
          'enable-ecs-log-metadata': 'true',
          'config-file-value': '/fluent-bit/configs/parse-json.conf',
        },
      },
      logConfiguration: {
        logDriver: 'awslogs',
        options: {
          'awslogs-group': '/aws/ecs/' + service,
          'awslogs-region': 'eu-west-1',
          'awslogs-create-group': 'true',
          'awslogs-stream-prefix': service,
        },
      },
      essential: false,
    },
    {
      name: 'datadog-agent',
      image: 'public.ecr.aws/datadog/agent:latest',
      environment: [
        {
          name: 'DD_APM_ENABLED',
          value: 'true',
        },
        {
          name: 'DD_REMOTE_CONFIGURATION_ENABLED',
          value: 'true',
        },
        {
          name: 'ECS_FARGATE',
          value: 'true',
        },
      ],
      secrets: [{
        name: 'DD_API_KEY',
        valueFrom: '/global/-',
      }],
      logConfiguration: {
        logDriver: 'awslogs',
        options: {
          'awslogs-group': '/aws/ecs/' + service,
          'awslogs-region': 'eu-west-1',
          'awslogs-create-group': 'true',
          'awslogs-stream-prefix': service,
        },
      },
      cpu: 10,
      memoryReservation: 256,
      essential: false,
      readonlyRootFilesystem: false,
      interactive: false,
      pseudoTerminal: false,
    },
  ],
}

Questions

1. Why would CPU/Memory metrics appear for one container (DataDog agent) but not for the main Kong container within the same task definition?
2. Is there a specific configuration required in the container definition to ensure CPU/Memory metrics are collected?
3. Are there known issues with Container Insights on ARM64 architecture?
4. Is there a way to debug what metrics are being collected/published for the specific containers?