CloudWatch alarms in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an AWS CloudWatch alarm?

An AWS CloudWatch alarm watches a specific metric and sends a notification or takes an action when the metric crosses a set threshold.

beginner

Which metric data can CloudWatch alarms monitor?

CloudWatch alarms can monitor metrics like CPU usage, disk reads/writes, network traffic, or custom metrics you send to CloudWatch.

intermediate

What happens when a CloudWatch alarm state changes to ALARM?

When the alarm state changes to ALARM, it can send notifications (like email or SMS) or trigger automated actions such as scaling resources.

beginner

How do you define the threshold for a CloudWatch alarm?

You set a threshold value and a comparison operator (like greater than or less than) that the metric must cross to trigger the alarm.

intermediate

Can CloudWatch alarms monitor multiple metrics at once?

No, each CloudWatch alarm monitors a single metric or a math expression based on metrics, but not multiple separate metrics directly.

What does a CloudWatch alarm do when a metric crosses its threshold?

A Deletes the resource

B Sends a notification or triggers an action

C Automatically fixes the issue

D Stops monitoring the metric

CloudWatch alarms notify or trigger actions when thresholds are crossed, but they do not delete resources or fix issues automatically.

Which of these can be used as a CloudWatch alarm action?

A Modify the metric data

B Change the AWS region

C Send an email notification

D Create a new AWS account

CloudWatch alarms can send notifications like emails or SMS, but cannot change regions, create accounts, or modify metric data.

What is required to create a CloudWatch alarm?

A A database instance

B An AWS IAM user only

C A CloudFormation template

D A metric and a threshold

To create a CloudWatch alarm, you need to specify a metric to watch and a threshold to trigger the alarm.

Can CloudWatch alarms monitor custom metrics?

A Yes, if you send custom metrics to CloudWatch

B No, only AWS default metrics

C Only metrics from EC2 instances

D Only metrics from S3 buckets

CloudWatch supports monitoring custom metrics that you send, not just default AWS metrics.

What state does a CloudWatch alarm enter when the metric is within normal range?

A OK

B ALARM

C INSUFFICIENT_DATA

D ERROR

When the metric is normal, the alarm state is OK. ALARM means threshold crossed, and INSUFFICIENT_DATA means not enough data.

Explain how a CloudWatch alarm works and what it can do when triggered.

Think about watching a number and reacting when it gets too high or low.

Describe the steps to create a CloudWatch alarm for monitoring CPU usage.

Imagine setting a speed limit and getting a warning if you go over.