You are the architect of a custom application running inside your corporate data center. The application runs with some unresolved bugs that produce a lot of data inside custom log files generating time-consuming activities for the operation team responsible for analyzing them.
You want to move the application to AWS using EC2 instances. At the same time, you want to take the opportunity to improve logging and monitoring capabilities, but without touching the application code.
What AWS service should you use to satisfy the requirement?

Answer options:

A.AWS Kinesis Data Streams
B.AWS CloudTrail
C.AWS CloudWatch Logs
D.AWS Application Logs

Answer: C
Option A is INCORRECT because in order to feed a Data Streams from custom logs you have to change the application code. AWS documentation describes this with the following sentence: “To put data into the stream, you must specify the name of the stream, a partition key, and the data blob to be added to the stream.”
Option B is INCORRECT because it is not related to the scenario and custom log files.
Option C is CORRECT because AWS CloudWatch Logs has the capability to reuse existing application logs increasing efficiency in operation with the ability to generate on them metrics, alerts and analytics with AWS CloudWatch Logs Insight.
The application and custom log files are exactly as they were when the application was running on-prem. So you don’t need to change any piece of application code that makes them ingestible by AWS CloudWatch Logs.
AWS official documentation in the FAQ section highlights the reusing capability with the sentence “AWS CloudWatch Logs lets you monitor and troubleshoot your systems and applications using your existing system, application and custom log files… so, no code changes are required.”
You can also leverage CloudWatch Metrics, Alarms and Dashboards with Logs to get full operational visibility into your applications. This empowers you to understand your applications, make improvements, and find problems quickly. Thus you can continue to innovate rapidly.
Option D is INCORRECT because AWS Application Logs does not exist.
Diagram: none
References:
https://aws.amazon.com/cloudwatch/faqs/