4.2.3 Implement Code that Emits Custom Metrics

import json

def handler(event, context):
    print(json.dumps({
        "_aws": {
            "Timestamp": 1705312200000,
            "CloudWatchMetrics": [{
                "Namespace": "MyApp",
                "Dimensions": [["Service"]],
                "Metrics": [{"Name": "ProcessingTime", "Unit": "Milliseconds"}]
            }]
        },
        "Service": "OrderService",
        "ProcessingTime": 150
    }))

import boto3

cw = boto3.client('cloudwatch')
cw.put_metric_data(
    Namespace='MyApp',
    MetricData=[{
        'MetricName': 'ActiveConnections',
        'Value': 42,
        'Unit': 'Count',
        'Dimensions': [{'Name': 'Service', 'Value': 'WebServer'}]
    }]
)

from aws_lambda_powertools import Metrics
from aws_lambda_powertools.metrics import MetricUnit

metrics = Metrics(namespace="MyApp")

@metrics.log_metrics(capture_cold_start_metric=True)
def handler(event, context):
    metrics.add_metric(name="OrdersProcessed", unit=MetricUnit.Count, value=1)