By default, AWS CloudWatch does not collect the memory metrics from the EC2 Instances. In order to get the memory usage we need to need to install the CloudWatch Agent on EC2 Instance. In this blog, we will install the AWS CloudWatch agent using AWS System Manager & collect memory metrics in the AWS CloudWatch console, after that we will create an alarm in AWS CloudWatch which will send an alert email notification when the memory usage goes above 75% using AWS SNS topic.