Announcing new Amazon CloudWatch Metrics for AWS Lambda Event Source Mappings (ESMs)

AWS Lambda announces new Amazon CloudWatch metrics for Lambda Event Source Mappings (ESMs), which provide customers visibility into the processing state of events read by ESMs that subscribe to Amazon SQS, Amazon Kinesis, and Amazon DynamoDB event sources. This enables customers to easily monitor issues or delays in event processing and take corrective actions. Customers use ESMs to read events from event sources and invoke Lambda functions. Lack of visibility into processing state of events ingested by ESMs delays diagnosis of event processing issues. Customers can now use the following CloudWatch metrics to monitor the processing state of events ingested by ESMs — PolledEventCount, InvokedEventCount, FilteredOutEventCount, FailedInvokeEventCount, DeletedEventCount, DroppedEventCount, and OnFailureDestinationDeliveredEventCount. _PolledEventCount_ counts the events read by an ESM, and _InvokedEventCount_ counts the events that invoked a Lambda function. _FilteredOutEventCount_ counts the events filtered out by an ESM. _FailedInvokeEventCount_ counts the events that attempted to invoke a Lambda function, but encountered failure. _DeletedEventCount_ counts the events that have been deleted from the SQS queue by Lambda upon successful processing. _DroppedEventCount_ counts the events dropped due to event expiry or exhaustion of retry attempts. _OnFailureDestinationDeliveredEventCount_ counts the events successfully sent to an [on-failure destination](https://docs.aws.amazon.com/lambda/latest/dg/kinesis-on-failure-destination.html). This feature is generally available in all [AWS Commercial Regions](https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services/) where AWS Lambda is available. You can enable ESM metrics using Lambda event source mapping API, AWS Console, AWS CLI, AWS SDK, AWS CloudFormation, and AWS SAM. To learn more about these metrics, visit [Lambda developer guide](https://docs.aws.amazon.com/lambda/latest/dg/monitoring-metrics-types.html). These new metrics are charged at standard [CloudWatch pricing](https://aws.amazon.com/cloudwatch/pricing/) for metrics.