CloudWatch dashboards in AWS - Commands & Configuration

Introduction

CloudWatch dashboards help you see important information about your cloud resources in one place. They show graphs and numbers that update automatically so you can watch how your apps and servers are doing.

When you want to track how much CPU your servers are using over time.

When you need to see if your website is getting more visitors or less.

When you want to watch error rates in your app to catch problems early.

When you want to combine data from different services into one view.

When you want to share system status with your team easily.

Config File - dashboard.json

dashboard.json

{
  "widgets": [
    {
      "type": "metric",
      "x": 0,
      "y": 0,
      "width": 12,
      "height": 6,
      "properties": {
        "metrics": [
          ["AWS/EC2", "CPUUtilization", "InstanceId", "i-0123456789abcdef0"]
        ],
        "period": 300,
        "stat": "Average",
        "region": "us-east-1",
        "title": "EC2 CPU Utilization"
      }
    }
  ]
}

This JSON file defines a CloudWatch dashboard with one widget.

• widgets: The list of visual blocks on the dashboard.
• type: The widget type, here a metric graph.
• metrics: The data shown, here CPU use of one EC2 instance.
• period: How often data points update, in seconds.
• stat: The statistic shown, average CPU use.
• region: AWS region of the data.
• title: The widget's label on the dashboard.

Commands

This command creates or updates a CloudWatch dashboard named 'MyDashboard' using the JSON file. It sets up the dashboard with the widgets defined in the file.

Terminal

aws cloudwatch put-dashboard --dashboard-name MyDashboard --dashboard-body file://dashboard.json

Expected Output

{"DashboardValidationMessages":[]}

→

--dashboard-name - Specifies the name of the dashboard to create or update.

→

--dashboard-body - Provides the JSON content of the dashboard from a file.

This command retrieves the details of the dashboard named 'MyDashboard' so you can verify it was created correctly.

Terminal

aws cloudwatch get-dashboard --dashboard-name MyDashboard

Expected Output

{"DashboardName":"MyDashboard","DashboardArn":"arn:aws:cloudwatch::123456789012:dashboard/MyDashboard","DashboardBody":"{\"widgets\":[{\"type\":\"metric\",\"x\":0,\"y\":0,\"width\":12,\"height\":6,\"properties\":{\"metrics\":[[\"AWS/EC2\",\"CPUUtilization\",\"InstanceId\",\"i-0123456789abcdef0\"]],\"period\":300,\"stat\":\"Average\",\"region\":\"us-east-1\",\"title\":\"EC2 CPU Utilization\"}}]}"}

→

--dashboard-name - Specifies the dashboard to retrieve.

This command lists all CloudWatch dashboards in your account so you can see your dashboard among them.

Terminal

aws cloudwatch list-dashboards

Expected Output

{"DashboardEntries":[{"DashboardName":"MyDashboard","DashboardArn":"arn:aws:cloudwatch::123456789012:dashboard/MyDashboard"}]}

Key Concept

If you remember nothing else from this pattern, remember: CloudWatch dashboards let you see important cloud data in one place with easy-to-understand graphs.

Common Mistakes

Using incorrect JSON format in the dashboard file.

CloudWatch rejects dashboards with invalid JSON, so the dashboard won't be created.

Validate your JSON file with a JSON linter before running the put-dashboard command.

Not specifying the correct AWS region for metrics.

Metrics from the wrong region won't show up, making the dashboard empty or misleading.

Always set the 'region' field in the widget properties to the region where your resources run.

Using the wrong instance ID or metric name.

The dashboard will show no data if the metric or resource does not exist.

Double-check resource IDs and metric names before adding them to the dashboard JSON.

Summary

Create a dashboard JSON file defining widgets and metrics to display.

Use 'aws cloudwatch put-dashboard' to create or update the dashboard with your JSON file.

Verify the dashboard creation with 'aws cloudwatch get-dashboard' and list dashboards with 'aws cloudwatch list-dashboards'.

Practice

1. What is the main purpose of an AWS CloudWatch dashboard?

easy

A. To deploy new cloud servers automatically

B. To store backups of cloud data

C. To visually display cloud resource metrics in one place

D. To manage user permissions for AWS services

Solution

1. Step 1: Understand CloudWatch dashboard function

   CloudWatch dashboards collect and show metrics visually for easy monitoring.

2. Step 2: Compare options with dashboard purpose

   Only To visually display cloud resource metrics in one place describes visual display of metrics; others describe unrelated tasks.

3. Final Answer:

   To visually display cloud resource metrics in one place -> Option C

4. Quick Check:

   Dashboard = Visual metrics display [OK]

Hint: Dashboards show metrics visually, not manage or store data [OK]

Common Mistakes:

• Confusing dashboards with backup storage
• Thinking dashboards manage permissions
• Assuming dashboards deploy servers

2. Which JSON element is required to add a widget to a CloudWatch dashboard?

easy

A. "widgets" array containing widget objects

B. "servers" array listing EC2 instances

C. "permissions" object defining access rights

D. "backups" array for snapshot data

Solution

1. Step 1: Identify JSON structure for dashboards

   CloudWatch dashboards use a "widgets" array to hold widget definitions.

2. Step 2: Eliminate unrelated JSON elements

   Options A, B, and D relate to servers, permissions, or backups, not widgets.

3. Final Answer:

   "widgets" array containing widget objects -> Option A

4. Quick Check:

   Widgets array = dashboard widgets [OK]

Hint: Widgets array holds dashboard widgets in JSON [OK]

Common Mistakes:

• Using 'servers' instead of 'widgets'
• Confusing permissions with widget data
• Including backups in dashboard JSON

3. Given this widget JSON snippet for a CloudWatch dashboard:

{"type": "metric", "x": 0, "y": 0, "width": 6, "height": 6, "properties": {"metrics": [["AWS/EC2", "CPUUtilization", "InstanceId", "i-1234567890abcdef0"]], "period": 300, "stat": "Average"}}

What metric will this widget display?

medium

A. Total network traffic of all EC2 instances

B. Average CPU utilization of the specified EC2 instance

C. Disk read operations for the specified EC2 instance

D. Memory usage of the specified EC2 instance

Solution

1. Step 1: Analyze the metric details in JSON

   The metric is "CPUUtilization" for AWS/EC2 with a specific InstanceId, using average statistic.

2. Step 2: Match metric to options

   Average CPU utilization of the specified EC2 instance matches CPU utilization average; others mention different metrics not in JSON.

3. Final Answer:

   Average CPU utilization of the specified EC2 instance -> Option B

4. Quick Check:

   Metric name = CPUUtilization [OK]

Hint: Look for metric name and stat in properties.metrics [OK]

Common Mistakes:

• Confusing CPU with network or disk metrics
• Ignoring the InstanceId filter
• Assuming memory metric without it specified

4. You uploaded a CloudWatch dashboard JSON but the widgets do not appear. Which is the most likely error?

medium

A. The JSON is missing the required "widgets" array

B. The EC2 instances are stopped

C. The AWS region is incorrect in the AWS CLI configuration

D. The IAM user lacks S3 bucket permissions

Solution

1. Step 1: Identify JSON structure requirement

   CloudWatch dashboards require a "widgets" array; missing it means no widgets show.

2. Step 2: Evaluate other options for widget display

   Stopped EC2 or region mismatch may affect metrics but not widget display; S3 permissions unrelated.

3. Final Answer:

   The JSON is missing the required "widgets" array -> Option A

4. Quick Check:

   Missing widgets array = no widgets shown [OK]

Hint: Always check for 'widgets' array in dashboard JSON [OK]

Common Mistakes:

• Blaming stopped instances for widget display
• Confusing region config with dashboard JSON
• Assuming S3 permissions affect dashboards

5. You want a CloudWatch dashboard to show CPU utilization for multiple EC2 instances side by side. Which JSON widget configuration approach is best?

hard

A. Add a text widget listing instance IDs

B. Create multiple dashboards, one per instance

C. Use a single metric widget without specifying InstanceId

D. Create one widget with multiple metrics, each metric for one instance

Solution

1. Step 1: Understand dashboard widget capabilities

   A single widget can show multiple metrics side by side by listing each instance's CPU metric.

2. Step 2: Evaluate other options for efficiency and clarity

   Multiple dashboards (B) is inefficient; single metric without InstanceId (C) aggregates all instances; text widget (D) does not show metrics.

3. Final Answer:

   Create one widget with multiple metrics, each metric for one instance -> Option D

4. Quick Check:

   Multiple metrics in one widget = side-by-side display [OK]

Hint: Use multiple metrics in one widget for side-by-side comparison [OK]

Common Mistakes:

• Creating separate dashboards wastes effort
• Omitting InstanceId shows combined data, not per instance
• Using text widgets instead of metric widgets