AWS CloudWatch: Setting up Alarms and Monitoring Logs

Lesson Objectives

By the end of this lesson, you will:

1. Understand what AWS CloudWatch is and its role in monitoring AWS resources.
2. Learn how to use CloudWatch for metrics, alarms, and log monitoring.
3. Configure CloudWatch Alarms to notify you of critical events.
4. Set up log monitoring to gain insights into application performance.

Introduction: Staying in Control

Imagine running a mission-critical web application. If your EC2 instances face high CPU usage or your application generates errors, you want to know immediately. AWS CloudWatch helps you monitor your AWS environment, track metrics, and set alarms to respond to issues before they impact users.

CloudWatch acts as your eyes and ears in AWS, providing real-time insights into resource performance, system health, and operational trends. In this chapter, we’ll configure metrics, alarms, and logs for a proactive approach to monitoring.

What is AWS CloudWatch?

AWS CloudWatch is a monitoring and observability service that provides data and actionable insights for AWS resources, applications, and on-premises servers.

Key Features:

1. Metrics: Collect and visualize performance data for AWS resources.
2. Alarms: Notify you when metrics cross defined thresholds.
3. Logs: Centralize log data from applications and services.
4. Dashboards: Create visual reports for an at-a-glance view of system health.
5. Events: Respond to changes in your environment using automated workflows.

Step-by-Step Lab: Setting Up CloudWatch Alarms and Logs

Scenario: Monitor an EC2 instance for high CPU usage and set up log monitoring for an application.

Part 1: Monitoring Metrics with CloudWatch

Step 1: Access CloudWatch

1. Log in to AWS:
   • Navigate to the AWS Management Console.
   • Search for CloudWatch and open the service.
2. View Metrics:
   • In the left-hand menu, click Metrics.
   • Choose EC2 > Per-Instance Metrics.
   • Select the EC2 instance you want to monitor.

Step 2: Create a CloudWatch Alarm

1. Navigate to Alarms:
   • Click Alarms > Create Alarm.
2. Choose a Metric:
   • Click Select Metric and find the CPUUtilization metric for your EC2 instance.
3. Set Conditions:
   • Define the threshold:
     • If CPUUtilization > 80% for 5 consecutive minutes.
4. Configure Actions:
   • Set up an SNS Topic for notifications:
     • Click Create Topic and name it HighCPUAlarm.
     • Add your email address to receive notifications.
5. Name and Create the Alarm:
   • Name the alarm HighCPUAlarm and click Create Alarm.

Part 2: Monitoring Logs with CloudWatch

Step 1: Configure CloudWatch Logs for an EC2 Instance

1. Install CloudWatch Agent:
   • SSH into your EC2 instance:
     

     
     ssh -i “your-key.pem” ec2-user@your-ec2-public-ip
     

   • Install the CloudWatch agent:
     

     
     sudo yum install amazon-cloudwatch-agent -y
     

2. Configure the Agent:
   • Create a configuration file:
     

     
     sudo nano /opt/aws/amazon-cloudwatch-agent/bin/config.json
     

   • Add the following configuration for monitoring logs:
     

     
     {
         “logs”: {
             “logs_collected”: {
                 “files”: {
                     “collect_list”: [
                         {
                             “file_path”: “/var/log/messages”,
                             “log_group_name”: “MyApplicationLogs”,
                             “log_stream_name”: “{instance_id}”
                         }
                     ]
                 }
             }
         }
     }
     

3. Start the Agent:
   • Start the CloudWatch agent:
     

     
     sudo /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a start
     

Step 2: View Logs in CloudWatch

1. Navigate to Logs:
   • In the CloudWatch console, click Logs > Log Groups.
   • Find and open the log group MyApplicationLogs.
2. Analyze Logs:
   • View log streams and search for specific entries or patterns (e.g., errors).

Reflection: Why Use CloudWatch?

AWS CloudWatch enables proactive monitoring of your AWS resources. In this lab, you:

1. Monitored EC2 instance metrics and set up alarms for critical thresholds.
2. Configured log monitoring to gain visibility into application behavior.
3. Responded to alarms with notifications and potential automation.

These skills are crucial for maintaining application reliability and reducing downtime.

What’s Next?

In the next chapter, we’ll explore Cost Management Tools, including Cost Explorer and Budgets, to optimize your AWS spending.

Your monitoring and optimization journey is underway—let’s continue building!