Reason for this change

Lambda is introducing a new property in Event Sources named MetricsConfig to get enhanced metrics for user's event source that captures each stage of processing. Through this metrics customer can track flow of events through their EDA pipelines.

This feature is currently supported for DynamoDB, Kinesis and SQS event sources only.

Description of changes

This new property can be opted in by setting the MetricsConfig field while creating event sources. The example of opting for MetricsConfig for dynamoDB event is shown below:

fn.addEventSource(new eventsources.DynamoEventSource(table, {
  startingPosition: lambda.StartingPosition.LATEST,
  metricsConfig: {
    metrics: [MetricType.EVENT_COUNT],
  }
}))

Today there is only 1 metric type: EventCount. The metrics array can be either one element with EventCount or an empty array. More configuration support will be available in future

Description of how you validated changes

Have added unit test and integration test to validate the implementation

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license