Introduction 

Amazon CloudWatch is a powerful monitoring service offered by Amazon Web Services (AWS) that provides comprehensive insights into your AWS resources, applications, and services. It allows you to collect and track metrics, collect and monitor log files, and set alarms. In this article, we will explore what CloudWatch is, where and when it is used, and how you can utilize it effectively. 

 
 
What is Amazon CloudWatch? 
 
 
 
 
 
Amazon CloudWatch monitors your AWS resources and the applications you run on there in real time. You can use CloudWatch to collect and track metrics, which are variables you can measure for your resources and applications.  
 
The CloudWatch home page automatically displays metrics about every AWS service you use. You can additionally create custom dashboards to display metrics about your custom applications, and display custom collections of metrics that you choose. You can create alarms which watch metrics and send notifications or automatically make changes to the resources you are monitoring when a threshold is breached.  
 
For example, you can monitor the CPU usage and disk reads and writes of your Amazon EC2 instances and then use this data to determine whether you should launch additional instances to handle the increased load. You can also use this data to stop under-utilized instances to save money.  
 
With CloudWatch, you gain system-wide visibility into resource utilization, application performance, and operational health. 
 
Accessing CloudWatch  
 
You can access CloudWatch using any of the following methods:  

 
• Amazon CloudWatch console — https://console.aws.amazon.com/cloudwatch/  
• AWS CLI — For more information, see Getting Set Up with the AWS Command Line  Interface in the AWS Command Line Interface User Guide.  
• CloudWatch API — For more information, see the Amazon CloudWatch API Reference. 
• AWS SDKs — For more information, see Tools for Amazon Web Services. 
 
 

Key Points for AWS CloudWatch 

Metrics and Alarms 

• CloudWatch collects and stores metrics, which are data points representing various aspects of your AWS resources. 

• Alarms enable you to monitor metrics and be notified in case of issues and/or perform automated actions based on predefined thresholds. 

Dashboard and Custom Metrics 

• You can create custom dashboards to visualize and analyze your metrics. 

• CloudWatch allows you to define custom metrics for monitoring specific application data. 

Logs and Log Insights 

• CloudWatch Logs provides the ability to ingest, store, and analyze log data from various AWS services. 

• Log Insights allows you to query log data with SQL-like queries. 

Integration and Notifications 

• CloudWatch can integrate with other AWS services like SNS (Simple Notification Service) to send notifications when alarms are triggered. 

• You can also use Lambda functions to execute automated actions in response to alarms. 

Benefits of using AWS CloudWatch 
 

What are the benefits of using Amazon Web Services CloudWatch? 

• Setting up alerts and rules is simpler when you use the new one-click option. With just one click, CloudWatch Application Insights is launched. The underlying resources in your account are automatically identified by Application Insights, which also helps to set alarms to monitor AWS applications. 

• One of the biggest advantages of CloudWatch is that you can access all your data from a single platform, which facilitates the deconstruction of data silos (server, network, database, etc.) and enables you to gain system-wide visibility and address the issues quickly. 

• The CloudWatch alarms monitor metrics values relative to thresholds that are either set by the CloudWatch using machine learning models to detect unusual activity or specified by the user. AWS CloudWatch can perform immediate actions to activate Amazon EC2 Auto Scaling or terminate an instance if an alarm is generated. 

• In addition to monitoring the Amazon Web Services or AWS environment, CloudWatch also keeps track of apps hosted locally or on Amazon Elastic Compute Cloud (EC2) and any other AWS environment. On automated dashboards, metrics and logs are acquired at every step of the performance stack. 

Where is AWS CloudWatch Used? 

AWS CloudWatch is used in various scenarios, including: 

1. Monitoring EC2 Instances: CloudWatch can monitor the performance of your Amazon Elastic Compute Cloud (EC2) instances. 

2. Managing Auto Scaling: It can automatically adjust the number of Amazon EC2 instances in an Auto Scaling group. 

3. Monitoring AWS Lambda Functions: CloudWatch provides metrics and logs for AWS Lambda functions. 

4. Tracking AWS S3 Bucket Metrics: You can monitor Amazon Simple Storage Service (S3) bucket metrics with CloudWatch. 

5. Monitoring RDS Databases: It can monitor Amazon RDS database instances. 

6. Logging and Monitoring for ECS and EKS: CloudWatch provides insights into containerized applications running on Amazon ECS and EKS. 

When to Use AWS CloudWatch? 

You should consider using AWS CloudWatch when: 

• You need to monitor your AWS resources and applications in real-time. 

• You want to set up alarms to notify you when specific thresholds are breached. 

• You need detailed insights into the performance and utilization of your resources. 

• You want to collect and analyze log data from your applications. 
   
   

How to Use AWS CloudWatch: A Step-by-Step Approach 

Step 1: Sign in to the AWS Console 

Navigate to the AWS Management Console and sign in using your credentials. 

Step 2: Open CloudWatch Dashboard 

In the AWS Management Console, search for “CloudWatch” in the services search bar and click on the CloudWatch service. 

Step 3: Understanding CloudWatch Concepts 

Familiarize yourself with CloudWatch concepts like Metrics, Alarms, Dashboards, Logs, and Events. You can find detailed documentation in the CloudWatch Concepts section. 

Step 4: Navigating the CloudWatch Interface 

Explore the CloudWatch interface, including the navigation pane on the left and the main content area. This is where you’ll access metrics, alarms, and other features. 

Step 5: Create Alarms 

Set up alarms to monitor specific metrics and receive notifications when thresholds are breached. Refer to the Creating Amazon CloudWatch Alarms documentation. 

Step 6: Create Custom Dashboards 

Build custom dashboards to visualize your metrics and gain insights into your AWS resources. You can learn how to do this in the Creating a CloudWatch Dashboard guide. 

Step 7: Analyze Logs with CloudWatch Logs 

If you want to collect and analyze log data, dive into the Amazon CloudWatch Logs documentation 

How Amazon CloudWatch Works 
 

Amazon CloudWatch is basically a metrics repository. An AWS service—such as Amazon EC2—puts metrics into the repository, and you retrieve statistics based on those metrics. If you put your own custom metrics into the repository, you can retrieve statistics on these metrics as well.  
 
 

You can use metrics to calculate statistics and then present the data graphically in the CloudWatch console. For more information about the other AWS resources that generate and send metrics to CloudWatch 

You can configure alarm actions to stop, start, or terminate an Amazon EC2 instance when certain criteria are met. In addition, you can create alarms that initiate Amazon EC2 Auto Scaling and Amazon Simple Notification Service (Amazon SNS) actions on your behalf. For more information about creating CloudWatch alarms 

AWS Cloud computing resources are housed in highly available data center facilities. To provide additional scalability and reliability, each data center facility is in a specific geographical area, known as a region. 

 Each region is designed to be completely isolated from the other regions, to achieve the greatest possible failure isolation and stability. Amazon CloudWatch does not aggregate data across regions. Therefore, metrics are separate between regions. 
 
 
Using Amazon CloudWatch Dashboards 
 
Amazon CloudWatch dashboards are customizable home pages in the CloudWatch console that you can use to monitor your resources in a single view, even those resources that are spread across different Regions. You can use CloudWatch dashboards to create customized views of the metrics and alarms for your AWS resources. 
 
With dashboards, you can create the following:  

 
• A single view for selected metrics and alarms to help you assess the health of your resources and applications across one or more regions. You can select the color used for each metric on each graph, so that you can easily track the same metric across multiple graphs.  

 
• An operational playbook that provides guidance for team members during operational events about how to respond to specific incidents. 

 
• A common view of critical resource and application measurements that can be shared by team members for faster communication flow during operational events. You can create dashboards by using the console, the AWS CLI, or by using the PutDashboard API. 
 
 

Accessing CloudWatch Logs for Lambda 
 
AWS Lambda automatically monitors Lambda functions for us, reporting metrics through Amazon CloudWatch. To help us troubleshoot failures in a function, Lambda logs all requests handled by our function, and automatically stores logs generated by our code through Amazon CloudWatch Logs. 

We can insert logging statements into our code to help us validate that our code is working as expected. 

 
 
In this simple example, we create a Lambda function to consume events published by Amazon S3. For any object uploaded to a bucket, S3 will invoke our Lambda function by passing event information in the form of function parameters.  
 
AWS Lambda executes the function. As the function executes, it reads the S3 event data, logs some of the event information to Amazon CloudWatch. This is an example of the “push” model where Amazon S3 invokes the Lambda function. 
 
 
 

Conclusion 

AWS CloudWatch is an indispensable tool for monitoring the performance and health of your AWS resources, ensuring their optimal operation. By understanding the key concepts and practices outlined in this article, you can confidently set up CloudWatch alarms to keep a close eye on your EC2 instances and trigger automated actions when needed.  

Whether you’re preparing for certification exams or managing real-world AWS deployments, CloudWatch is a valuable asset for maintaining the reliability and efficiency of your cloud infrastructure. 

Happy Learning 😉