You have a set of web servers hosted in AWS which host a web application used by a section of users. You want to monitor the number of errors which occur when using the web application. Which of the below options can be used for this purpose. Choose 3 answers from the options given below.

Answer options:

A.Send the logs from the instances onto Cloudwatch logs.
B.Search for the keyword “ERROR” in the log files on the server.
C.Search for the keyword “ERROR” in Cloudwatch logs.
D.Increment a metric filter in Cloudwatch whenever the pattern is matched.

Answer – A,C and D
The AWS documentation mentions the following
You use metric filters to search for and match terms, phrases, or values in your log events. When a metric filter finds one of the terms, phrases, or values in your log events, you can increment the value of a CloudWatch metric. For example, you can create a metric filter to search for and count the occurrence of the word ERROR in your log events.
For more information on Cloudwatch logs – Filter and pattern matching , please refer to the below link:
http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/FilterAndPatternSyntax.html