Monitoring

Question 1

What is CloudWatch?

Answer 1

It is a monitoring service that monitors your AWS resources, as well as the applications that you run on AWS.

Question 2

What does CloudWatch monitor per default (host level metrics)?

Answer 2

• CPU
• Network
• Disk (e.g. disk I/O, not how much storage there is left)
• Status Check (e.g. health of a EC2 host or instance)

Question 3

Name a CloudWatch custom metric.

Answer 3

RAM Utilization

Question 4

What is the default monitoring for EC2 (in minutes)?

Answer 4

Default is 5 minutes intervals. You can enable detailed monitoring, which makes it 1 minute intervals.

Question 5

What is the retention period for CloudWatch logs?

Answer 5

CloudWatch stores your logs indefinitely by default. You can change this. You can even retrieve data from terminated EC2 or ELB instances after its termination.

Question 6

What is the minimum granularity for CloudWatch custom metrics?

Answer 6

1 minute.

Question 7

How can you use CloudWatch to monitor?

Answer 7

• You can create an alarm to monitor any CloudWatch metric in your account
• e.g. EC2 CPU utilization, Elastic Load Balancer latency, charches on you AWS bill
• You can set a threshold in which to trigger the alarm, and also set what action should be taken if an alarm state is reached (SNS that sends you a notification, Lambda that terminates some instances, etc).

Question 8

What is the metric granularity for Standard and Detailed monitoring?

Answer 8

Standard: 5 min
Detailed: 1 min

Question 9

Can CloudWatch be used on premise?

Answer 9

Yes. Just need to download an install the SSM agent and CloudWatch agent.

Question 10

What is the difference between CloudWatch, CloudTrail and Config?

Answer 10

• CloudWatch
• Monitors performance
• CloudTrail
• Monitors API calls in the AWS platform
• Used for auditing
• E.g. if I provision an EC2
• Tells you what time it was provisioned, what resource, whether it was provisioned successfully, who provisioned it, the IP address, etc.
• Config
• Records the state of your AWS environment and can notify you of changes
• E.g. Config can tell you what the rules was on a certain security group three weeks ago

Question 11

How do I delete CloudWatch metrics?

Answer 11

“Metrics cannot be deleted, but they automatically expire after 15 months if no new data is published to them.”