Concepts
The CloudWatch agent is a software package that you can install on your EC2 instances and on-premises servers to collect metrics and logs. It can capture system-level metrics such as CPU usage, memory, disk, and network stats, as well as collect detailed log data from the operating system and applications. The agent supports both Linux and Windows operating systems.
Setting up the CloudWatch Agent
Prerequisites
- Ensure the instance has an IAM role with the necessary permissions to send metrics and logs to CloudWatch.
- Make sure your instance has internet connectivity, or if VPC endpoints are used, set them up accordingly.
Installation
- To install the CloudWatch agent, you can use either the AWS Command Line Interface (CLI) or manually download and install it.
- For Amazon Linux, you can simply use
yumto install the agent:
sudo yum install -y amazon-cloudwatch-agent - For other Linux-based systems and Windows, you can download the package and follow the installation instructions provided in the AWS documentation.
Configuration
- The CloudWatch agent is configured via a JSON file. You can create this file manually, or use the
amazon-cloudwatch-agent-config-wizard, which simplifies the process. - After running the wizard, you will have a file named
config.jsoncontaining your specified metrics and logs. - This configuration file needs to be placed in the correct directory for the CloudWatch agent to read from or uploaded to the Systems Manager Parameter Store.
Starting the Agent
- On Linux, the agent can be started with the following command:
sudo /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -c file:/opt/aws/amazon-cloudwatch-agent/bin/config.json -s - On Windows, use the corresponding command in PowerShell or the Command Prompt.
Monitoring and Troubleshooting
Once the agent is running, it will begin sending the specified metrics and logs to CloudWatch. You can view these metrics through the AWS Management Console or retrieve them using the AWS CLI or SDKs. Alarms can be set up based on the metrics collected, triggering notifications or automations if certain thresholds are crossed or anomalies are detected.
For troubleshooting, the agent itself generates logs, which can help in understanding any issues with the agent’s performance or configuration.
Example: Monitoring Memory and Disk Metrics
In your config.json, you might specify additional metrics like memory and disk usage which are not collected by default:
{
“metrics”: {
“metrics_collected”: {
“mem”: {
“measurement”: [
“mem_used_percent”
]
},
“disk”: {
“measurement”: [
“used_percent”
],
“resources”: [
“/”
]
}
}
}
}
This configuration would instruct the agent to collect the percentage of memory used and the percentage of disk space used on the root volume.
Comparison with AWS CloudWatch Logs
While the CloudWatch agent focuses on metrics and log files, CloudWatch Logs primarily captures, stores, and monitors log files. You might use CloudWatch Logs alongside the CloudWatch agent to collect and monitor different types of log data.
| Feature | CloudWatch Agent | CloudWatch Logs |
|---|---|---|
| Metrics Collection | Yes, system and application metrics | No |
| Log Data Collection | Yes, including custom log files | Yes, application log files |
| Operating System Support | Linux and Windows | Linux and Windows |
| Storage Retention | Customizable retention period for metrics | Customizable retention period for logs |
| Real-time Monitoring | Near real-time for metrics | Near real-time for logs |
| Predefined Metrics | Limited to EC2 by default, more with agent | No |
| Required Installation | Yes | No (if using AWS SDK or log streams) |
In summary, the CloudWatch agent is a versatile tool for AWS infrastructure monitoring which extends CloudWatch’s native capabilities. It’s essential for any SysOps Administrator to know how to deploy, configure, and troubleshoot the CloudWatch agent to ensure thorough monitoring and reliable performance of AWS or hybrid cloud environments. Remember to refer to AWS’s official documentation for the most updated and detailed instructions when preparing for the AWS Certified SysOps Administrator – Associate exam.
Answer the Questions in Comment Section
What type of data does the CloudWatch agent collect?
- A) Metrics only
- B) Logs only
- C) Both metrics and logs
- D) Security group configurations
Answer: C) Both metrics and logs
Explanation: The CloudWatch agent is capable of collecting both system-level metrics and logs from Amazon EC2 instances and on-premises servers.
The CloudWatch agent can be installed on which of the following operating systems?
- A) Amazon Linux only
- B) Windows Server only
- C) Both Amazon Linux and Windows Server
- D) All operating systems
Answer: C) Both Amazon Linux and Windows Server
Explanation: The CloudWatch agent supports multiple operating systems including Amazon Linux and Windows Server.
True or False: CloudWatch Logs can be used to monitor application logs.
Answer: True
Explanation: CloudWatch Logs can monitor, store, and access log files from EC2 instances, CloudTrail, and other sources, and can include application logs.
To send custom metrics to CloudWatch using the CloudWatch agent, which format should the metrics use?
- A) JSON
- B) CSV
- C) XML
- D) YAML
Answer: A) JSON
Explanation: The CloudWatch agent uses a JSON-formatted configuration file to specify what metrics to collect.
True or False: The CloudWatch agent can be configured via the AWS Management Console.
Answer: False
Explanation: The CloudWatch agent is configured through a JSON file or by using the `amazon-cloudwatch-agent-config-wizard` command-line tool, not through AWS Management Console directly.
Which AWS service can be used to centrally manage CloudWatch agent configurations across multiple instances?
- A) AWS Config
- B) AWS Systems Manager
- C) AWS Lambda
- D) AWS CloudFormation
Answer: B) AWS Systems Manager
Explanation: AWS Systems Manager can be used to centrally manage the CloudWatch agent configuration and ensure consistent deployment across multiple instances.
True or False: The CloudWatch agent only supports static configuration files.
Answer: False
Explanation: The CloudWatch agent supports both static and dynamic configuration. Dynamic configuration is facilitated by the use of the AWS Systems Manager Parameter Store.
What permission must an IAM role have to allow an EC2 instance to send logs to CloudWatch using the CloudWatch agent?
- A) AmazonEC2ReadOnlyAccess
- B) AmazonEC2FullAccess
- C) CloudWatchLogsFullAccess
- D) AmazonS3ReadOnlyAccess
Answer: C) CloudWatchLogsFullAccess
Explanation: The IAM role should have CloudWatchLogsFullAccess or similar permissions that allow actions on CloudWatch Logs for the agent to successfully send logs.
True or False: The CloudWatch agent cannot collect system metrics such as CPU usage, disk I/O, and memory utilization.
Answer: False
Explanation: The CloudWatch agent is specifically designed to collect detailed system-level metrics, including but not limited to CPU usage, disk I/O, and memory utilization.
To enable high-resolution metrics with the CloudWatch agent, what minimum granularity can be specified?
- A) 1 second
- B) 5 seconds
- C) 1 minute
- D) 5 minutes
Answer: A) 1 second
Explanation: The CloudWatch agent can be configured to collect high-resolution metrics at granularities as fine as 1 second.
Can CloudWatch agent collect logs from applications running inside Docker containers on EC2 instances?
- A) Yes, for all applications and configurations
- B) Yes, but additional configuration may be required
- C) No, it only collects logs from EC2 instance directly
- D) No, it requires an external tool like Fluentd
Answer: B) Yes, but additional configuration may be required
Explanation: The CloudWatch agent can collect logs from applications inside Docker containers on EC2 instances, but the correct logging driver or additional configuration might be needed to pipe logs to the agent.
Which of the following is NOT a benefit of using the CloudWatch agent?
- A) Enhanced metric resolution
- B) Log collection and monitoring
- C) Automatically scaling EC2 instances
- D) Centralized log management
Answer: C) Automatically scaling EC2 instances
Explanation: Automatically scaling EC2 instances is a function of Auto Scaling and not directly a benefit of the CloudWatch agent. The CloudWatch agent primarily collects metrics and logs.
Great article! I found the step-by-step instructions for setting up the CloudWatch agent very clear.
Thanks for this informative post. Can someone explain about the different types of logs that the CloudWatch agent can collect?
I’m setting up the CloudWatch agent on my EC2 instances. Should I use the unified CloudWatch agent or the older CloudWatch Logs agent?
How can I validate that my CloudWatch agent is installed and running correctly?
Just what I needed, thanks a lot!
Could you elaborate on the IAM permissions required for the CloudWatch agent?
This is really helpful for my AWS exam preparation. Thank you!
Any tips on optimizing the performance of the CloudWatch agent?