You have customized some system and application logs in EC2 instances and delivered them to several Log Groups in CloudWatch Logs. You find that it is very difficult to discover useful logs only through the AWS CloudWatch Logs console. You prefer to stream the logs out to a downstream processing system, providing more accurate and important information to the operations team. For which of the following services can you configure CloudWatch Logs and stream the data out? (Select TWO.)

Answer options:

A.AWS S3
B.AWS Lambda function
C.AWS Elasticsearch
D.AWS CloudTrail
E.AWS DynamoDB

Correct Answer – B, C
In CloudWatch Logs, subscriptions can be used to deliver log events to other services in real-time. About the details and supported services, please refer to https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/Subscriptions.html.
Option A is incorrect: Because S3 is not supported for CloudWatch Logs streaming. However, for S3, the logs can be exported to a bucket for a given time range. The reference is in
https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/S3Export.html.
Option B is CORRECT: Because AWS Logs has supported streaming data to Lambda:
Option C is CORRECT: Please check https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CWL_ES_Stream.html on how to stream CloudWatch Logs data to Elasticsearch.
Option D and E are incorrect: Because the service is not supported for CloudWatch Logs streaming.
Note: CloudWatch supports subscriptions for Lambda, Elasticsearch, Kinesis Data Streams (CLI only) and Kinesis Data Firehose (CLI only).