Example telemetry event in CloudWatch Lambda Insights

Each invocation of a Lambda function that has Lambda Insights enabled writes a single log event to the /aws/lambda-insights log group. Each log event contains metrics in embedded metric format. For more information about embedded metric format, see Embedding metrics within logs.

To analyze these log events, you can use the following methods:

The following is an example of a Lambda Insights log event with embedded metric format.

{
    "_aws": {
        "Timestamp": 1605034324256,
        "CloudWatchMetrics": [
            {
                "Namespace": "LambdaInsights",
                "Dimensions": [
                    [ "function_name" ],
                    [ "function_name", "version" ]
                ],
                "Metrics": [
                    { "Name": "memory_utilization", "Unit": "Percent" },
                    { "Name": "total_memory", "Unit": "Megabytes" },
                    { "Name": "used_memory_max", "Unit": "Megabytes" },
                    { "Name": "cpu_total_time", "Unit": "Milliseconds" },
                    { "Name": "tx_bytes", "Unit": "Bytes" },
                    { "Name": "rx_bytes", "Unit": "Bytes" },
                    { "Name": "total_network", "Unit": "Bytes" },
                    { "Name": "init_duration", "Unit": "Milliseconds" }
                ]
            }
        ],
        "LambdaInsights": {
            "ShareTelemetry": true
        }
    },
    "event_type": "performance",
    "function_name": "cpu-intensive",
    "version": "Blue",
    "request_id": "12345678-8bcc-42f7-b1de-123456789012",
    "trace_id": "1-5faae118-12345678901234567890",
    "duration": 45191,
    "billed_duration": 45200,
    "billed_mb_ms": 11571200,
    "cold_start": true,
    "init_duration": 130,
    "tmp_free": 538329088,
    "tmp_max": 551346176,
    "threads_max": 11,
    "used_memory_max": 63,
    "total_memory": 256,
    "memory_utilization": 24,
    "cpu_user_time": 6640,
    "cpu_system_time": 50,
    "cpu_total_time": 6690,
    "fd_use": 416,
    "fd_max": 32642,
    "tx_bytes": 4434,
    "rx_bytes": 6911,
    "timeout": true,
    "shutdown_reason": "Timeout",
    "total_network": 11345,
    "agent_version": "1.0.72.0",
    "agent_memory_avg": 10,
    "agent_memory_max": 10
}

The following is an example of a Lambda Insights log event for a Lambda function running on Lambda Managed Instances.

{
    "total_network": 16443,
    "tmp_free": 531492864,
    "total_memory": 2048,
    "fd_use": 85,
    "tmp_used": 11984896,
    "execution_environment_init": false,
    "version": "3",
    "event_type": "performance",
    "agent_memory_max": 6,
    "fd_max": 1024,
    "function_name": "cpu-intensive",
    "tx_bytes": 8404,
    "memory_utilization": 3,
    "used_memory_max": 73,
    "memory_utilization_max": 3,
    "cpu_system_time": 541,
    "threads_max": 49,
    "tmp_max": 543477760,
    "cpu_utilization_max": 2,
    "agent_memory_avg": 6,
    "cpu_total_time": 815,
    "rx_bytes": 8039,
    "lambda_mode": "managed-instance",
    "agent_version": "1.0.660.0",
    "_aws": {
        "CloudWatchMetrics": [
            {
                "Namespace": "LambdaInsights",
                "Dimensions": [
                    [
                        "function_name"
                    ],
                    [
                        "function_name",
                        "version"
                    ]
                ],
                "Metrics": [
                    {
                        "Name": "cpu_total_time",
                        "Unit": "Milliseconds"
                    },
                    {
                        "Name": "cpu_utilization",
                        "Unit": "Percent"
                    },
                    {
                        "Name": "cpu_utilization_max",
                        "Unit": "Percent"
                    },
                    {
                        "Name": "tx_bytes",
                        "Unit": "Bytes"
                    },
                    {
                        "Name": "rx_bytes",
                        "Unit": "Bytes"
                    },
                    {
                        "Name": "total_network",
                        "Unit": "Bytes"
                    },
                    {
                        "Name": "used_memory_max",
                        "Unit": "Megabytes"
                    },
                    {
                        "Name": "memory_utilization",
                        "Unit": "Percent"
                    },
                    {
                        "Name": "memory_utilization_max",
                        "Unit": "Percent"
                    },
                    {
                        "Name": "total_memory",
                        "Unit": "Megabytes"
                    },
                    {
                        "Name": "tmp_used",
                        "Unit": "Bytes"
                    },
                    {
                        "Name": "tmp_free",
                        "Unit": "Bytes"
                    }
                ]
            }
        ],
        "Timestamp": 1764164871353,
        "LambdaInsights": {
            "ShareTelemetry": true
        }
    },
    "cpu_utilization": 1,
    "cpu_user_time": 273
}