Monitoring your infrastructure with Amazon CloudWatch

Posted on by Panther

Overview

Amazon CloudWatch is a monitoring service provided by Amazon Web Services (AWS) that collects and tracks metrics, collects and monitors log files, and sets alarms. It can be used to monitor EC2 instances, load balancers, RDS instances, and other AWS resources, as well as custom metrics generated by your own applications and services.

In this tutorial, we will cover the basics of monitoring your infrastructure with Amazon CloudWatch. We will be using the AWS Management Console to create and manage CloudWatch resources, and we will be focusing on monitoring EC2 instances. We will cover the following topics:

  • Setting up CloudWatch and EC2 instances
  • Viewing EC2 instance metrics in CloudWatch
  • Creating CloudWatch Alarms
  • Monitoring Custom Metrics with CloudWatch
  • Viewing Logs with CloudWatch Logs

Setting up CloudWatch and EC2 instances

Before we get started with CloudWatch, let’s make sure we have some EC2 instances running to monitor. For this tutorial, we will use two instances: one Linux instance and one Windows instance. If you don’t have any EC2 instances running, you can follow the AWS documentation on launching instances.

Once you have some instances running, we can move on to setting up CloudWatch. If you haven’t used CloudWatch before, you may need to enable it for your account. To do this, go to the CloudWatch console in the AWS Management Console and click on the “Get Started” button. This will take you through the setup process and enable CloudWatch for your account.

Viewing EC2 instance metrics in CloudWatch

Once CloudWatch is enabled, you can view metrics for your EC2 instances. To do this, go to the CloudWatch console and click on “Metrics” in the left-hand menu. This will bring up a list of different AWS services that you can monitor with CloudWatch. Click on “EC2” to view EC2 instance metrics.

The EC2 metrics are organized by instance ID. Select the instance ID of the instance you want to view metrics for. This will show you a list of available metrics for that instance. Some of the default metrics include CPU usage, disk read/write, and network traffic.

To view the CPU utilization metric for your instance, select the instance ID and then select the “CPUUtilization” metric. This will bring up a graph of the metric over time. You can adjust the time range for the graph using the dropdown in the top-right corner of the page.

Creating CloudWatch Alarms

CloudWatch alarms allow you to set thresholds for your metrics and receive notifications when the threshold is breached. For example, you could set a threshold for CPU utilization and receive an email when your CPU utilization goes above a certain percentage.

To create an alarm, go to the CloudWatch console and select “Alarms” from the left-hand menu. Click on the “Create Alarm” button to create a new alarm.

You will be prompted to select the metric you want to alarm on, as well as the threshold and the period. The threshold is the value that triggers the alarm, and the period is the length of time over which the metric is evaluated.

For example, if you wanted to set an alarm for CPU utilization going above 80% over a 5-minute period, you would select the “CPUUtilization” metric, set the threshold to “80”, and set the period to “5 minutes”.

Once you have set up the alarm, you will need to configure the actions for the alarm. You can configure CloudWatch to send notifications to an SNS topic, an email address, or an SMS message. You can also configure the alarm to perform an action, such as stopping an instance, when the threshold is breached.

Monitoring Custom Metrics with CloudWatch

In addition to monitoring AWS resources, you can also use CloudWatch to monitor custom metrics generated by your own applications and services. To do this, you will need to use the CloudWatch API to send metrics to CloudWatch.

The CloudWatch API supports two types of metrics: standard metrics and custom metrics. Standard metrics are pre-defined by AWS and are available for all AWS services that are monitored by CloudWatch. Custom metrics are metrics that you define yourself.

To send custom metrics to CloudWatch, you will need to use the CloudWatch API to put a metric data point. The API allows you to specify the metric name, the metric value, and any dimensions associated with the metric.

Once you have sent some custom metrics, you can view them in the CloudWatch console by going to the Metrics page and selecting the “Custom Namespaces” option. This will show you a list of available custom namespaces, which are groups of related metrics. Selecting a namespace will show you the metrics for that namespace.

Viewing Logs with CloudWatch Logs

In addition to metrics, CloudWatch can also be used to monitor and analyze log files. CloudWatch Logs allows you to collect, monitor, and analyze log files from EC2 instances, AWS CloudTrail, and other sources.

To get started with CloudWatch Logs, you will need to create a log group and a log stream. A log group is a collection of log streams, and a log stream is a sequence of log events that share the same source.

To create a log group, go to the CloudWatch Logs console and click on “Create Log Group”. Give your log group a name and click “Create”.

Once you have created a log group, you can create a log stream. To do this, click on the log group you just created and click on “Create Log Stream”. Give your log stream a name and click “Create”.

Now that you have created a log stream, you can start sending log events to it. To do this, you will need to use the CloudWatch Logs API to put log events.

For example, if you wanted to send a log event to your log stream, you would use the following API call:

aws logs put-log-events 
    --log-group-name my-log-group 
    --log-stream-name my-log-stream 
    --log-events timestamp=$(date +%s000),message="Hello World"

This would send a log event to the “my-log-stream” stream in the “my-log-group” log group with a timestamp of the current time and a message of “Hello World”.

Once you have sent some log events, you can view them in the CloudWatch Logs console by selecting your log group and log stream. This will show you a list of log events for the stream. You can filter and search the log events using the search box in the top-right corner of the page.

Conclusion

Amazon CloudWatch is a powerful monitoring service that can be used to collect and track metrics, monitor log files, and set alarms. In this tutorial, we covered the basics of setting up CloudWatch and monitoring EC2 instances, creating alarms, monitoring custom metrics, and viewing logs with CloudWatch Logs. With these tools, you can gain visibility into your AWS resources and take action when issues arise.

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