Building Scalable Web Applications Using AWS CLI & WordPress/

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Try Out Health Checks

Try Out Health Checks

Learn how health checks help with scalability and high availability.

We'll cover the following...

Let’s see if our health checks work and how we can check them. We'll use the elbv2 describe-target-health command. We just need to pass the target group ARN via the --target-group-arn parameter. So, the command would look like this:

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aws elbv2 describe-target-health --target-group-arn <target-group-arn>

To get the target group ARN, we can use the describe-target-groups command again, just like we did in our last lesson. The full command, therefore, looks like this:

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aws elbv2 describe-target-health \
    --target-group-arn $(aws elbv2 describe-target-groups \
    --names wordpress-instances \
    --query 'TargetGroups[*].TargetGroupArn' \
    --output text)

Run the command in the terminal below:

Terminal 1
Terminal
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The output should be similar to this:

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{
    "TargetHealthDescriptions": [
        {
            "Target": {
                "Id": "i-0184ea1e52d5d5029",
                "Port": 80
            },
            "HealthCheckPort": "80",
            "TargetHealth": {
                "State": "healthy"
            }
        },
        {
            "Target": {
                "Id": "i-07ee1bd00625b312c",
                "Port": 80
            },
            "HealthCheckPort": "80",
            "TargetHealth": {
                "State": "healthy"
            }
        }
    ]
}

As we can see, both targets are healthy ( ...