What are custom CloudWatch metrics for EC2?

Custom CloudWatch metrics allow you to publish application-specific and system-level metrics beyond the default EC2 metrics (CPU, network, disk I/O). Examples include memory utilisation, disk space usage, application response times, custom counters, and any business metric — enabling comprehensive monitoring of your EC2 instances.

How do you send custom metrics to CloudWatch from an EC2 instance?

Send custom metrics to CloudWatch using: the AWS CLI command 'aws cloudwatch put-metric-data', the CloudWatch Agent (for memory and disk metrics), AWS SDKs (Python boto3, Node.js AWS SDK), or the CloudWatch Embedded Metrics Format (EMF) from Lambda and containers. The CloudWatch Agent is the recommended approach for OS-level metrics.

How do you monitor EC2 memory utilisation with CloudWatch?

Monitor EC2 memory utilisation with CloudWatch by installing the CloudWatch Agent on your EC2 instance, configuring it with the metrics you want to collect (mem_used_percent, disk_used_percent), and starting the agent service. The CloudWatch Agent automatically publishes these metrics every 60 seconds to CloudWatch.

How much do custom CloudWatch metrics cost?

CloudWatch custom metrics pricing: the first 10 metrics are free, then $0.30 per metric per month. Custom metrics are charged per metric per month regardless of data points. High-resolution metrics (1-second granularity) cost $0.02 per metric per month additionally. Most monitoring setups with 50-100 custom metrics cost $15-30/month.

AWS Custom CloudWatch Metrics for EC2: Setup & Step-by-Step Guide

December 28, 2020 / Nirav Shah

What Are Custom CloudWatch Metrics for AWS EC2? Complete Overview

As more and more organisations adopt AWS cloud for its obvious benefits, it becomes a known fact that AWS resources need to be monitored. For the same purpose, the most efficient AWS service is CloudWatch.

We can monitor our services like Amazon Web Services like EBS volumes, EC2 instances and RDS instances.

Today we understand about EC2 Monitoring via CloudWatch.

There are two types of monitoring

Basic Monitoring
Detailed Monitoring

In CloudWatch default monitoring, it does not enable memory utilization or disk I/O of the instances if we want we need to apply custom metrics for this.

How to Enable Custom CloudWatch Metrics for EC2 Step by Step

In this blog, we cover how to enable custom detail monitoring and collect memory and disk metrics using AWS CloudWatch agent.

Let’s get started and go step by step.

Step 1: First, we need to create an IAM role with CloudwatchagentServerPolicy

Custom Cloud watch Metrics for AWS EC2 Instance

Step 2: Now we need to launch an EC2 Instance with this role. And allow the port for HTTP-80

Custom Cloud watch Metrics for AWS EC2 Instance

Step 3: Now ssh the EC2 instance and Install httpd package.

    #yum install httpd
    #systemctl start httpd
    #system enable httpd

Custom Cloud watch Metrics for AWS EC2 Instance

Step 4: Install CloudWatch Agent

CloudWatch agent provides an automated way to send system log data to CloudWatch logs from the EC2 instance

The agent includes the following components:

A plug-in to AWS CLI that pushes log data to CloudWatch logs.
A Script that initiates the process to push data to Cloudwatch Logs.
A cron job that ensures that the daemon is always running.

After installing Agent there are two configurations file created at /etc/awslogs or /var/awslogs/etc directory

awsligs.conf → Which logs to be captured
awscli.conf → To which ASS region the logs to be sent

#cd /tmp 
#wget https://s3.amazonaws.com/amazoncloudwatch-agent/linux/amd64/latest/AmazonCloudWatchAgent.zip 
#unzip AmazonCloudWatchAgent.zip 
#./install.sh

Custom Cloud watch Metrics for AWS EC2 Instance

Step 5: Configure Metrics

In this step, we need to describe the metrics that we want to collect and send to CloudWatch, AWS CloudWatch agent will read that info from a JSON file

#/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-config-wizard

Custom Cloud watch Metrics for AWS EC2 Instance

Step 6: Start Cloudwatch agent

#mkdir -p /usr/share/collectd
#touch /usr/share/collectd/types.db
#/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
# /bin/systemctl restart amazon-cloudwatch-agent.service
#/bin/systemctl status amazon-cloudwatch-agent.service

Step 7: Now Create Cloudwatch Dashboard

We can see memory utilization from here

Custom Cloud watch Metrics for AWS EC2 Instance

Hit access webpage and see the log

Custom Cloud watch Metrics for AWS EC2 Instance

We can see our log here

Custom Cloud watch Metrics for AWS EC2 Instance

Conclusion

By this, we can create a custom log for the AWS EC2 instance and the same method can be used with other AWS services to gather data and attain valuable insights.

Thanks!! and stay tuned for more blogs.

Also Read –How To Start And Stop AWS EC2 Instance Using Lambda

Frequently Asked Questions: AWS Custom CloudWatch Metrics

What can I measure with Amazon CloudWatch Metrics?
What statistics can I view and graph in CloudWatch?
What log monitoring does Amazon CloudWatch provide?

Spread Love By Sharing:

Nirav Shah

Nirav Shah is the Director of Eternal Web Pvt Ltd, an AWS Advanced Consulting Partner and certified Odoo Partner based in the UK. With over a decade of experience in cloud computing, digital transformation, and ERP implementation, Nirav helps enterprises adopt the right technology to solve complex business challenges. He specialises in AWS infrastructure, Odoo ERP, and web development solutions for businesses across the UK and beyond.