Underutilized EC2 Instance

01 Sign in to the AWS Management Console.

02 Navigate to EC2 dashboard at https://console.aws.amazon.com/ec2/.

03 In the navigation panel, under INSTANCES section, choose Instances.

04 Select the EC2 instance that you want to examine.

05 Select the Monitoring tab from the dashboard bottom panel.

06 Within the CloudWatch metrics section, perform the following actions:

1. Click on the CPU Utilization (Percent) usage graph thumbnail to open the instance CPU usage details box. Inside the CloudWatch Monitoring Details dialog box, set the following parameters:
   • From the Statistic dropdown list, select Average.
   • From the Time Range list, select Last 1 Week.
   • From the Period dropdown list, select 1 Hour.
2. Once the monitoring data is loaded, verify the instance CPU usage for the last 7 days. If the average usage (percent) has been less than 60%, e.g. , the selected EC2 instance qualifies as candidate for the underused instance. Click X (close) to return to the dashboard.

07 Now determine the EC2 instance memory utilization by reading the EC2MemoryUtilization metric data reported by the CloudWatch agent (Perl script) installed on the selected EC2 instance (this rule assumes that the script has been successfully installed and it has returned memory usage data in the past 7 days). To verify the instance memory usage reported by the custom CloudWatch metric, perform the following actions:

1. Navigate to Cloudwatch dashboard at https://console.aws.amazon.com/cloudwatch/.
2. In the navigation panel, select Metrics to access your existing Cloudwatch metrics.
3. Choose All metrics tab from the dashboard bottom panel, click Linux System then select InstanceId to list any custom metrics installed on your EC2 instances.
4. Select the right EC2 instance from the list (see Audit section part I, step no. 4), click the Action dropdown button from the dashboard top-right menu then choose Add to dashboard option.
5. On Add to dashboard dialog box, perform the following:
   • Under Select a dashboard, click Create new button and provide a unique name for the new dashboard inside the Dashboard name box.
   • Within Select a widget type section, choose Number.
   • Review the settings then click Add to dashboard to create the required Cloudwatch dashboard and redirect to Dashboards page.
6. Click the Custom dropdown button from the dashboard top-right menu, select Relative then choose the 1 Weeks option to return the data recorded in the past week.
7. Once the monitoring data is available within the widget, verify the instance memory usage for the last 7 days. If the average usage (percent) has been less than 60%, e.g. , the selected EC2 instance qualifies as candidate for the underused instance.

If the rule conditions are met, based on the usage data outlined at step no. 6 and 7, the selected AWS EC2 instance is considered "underutilized" and can be safely downsized in order to stop incurring charges for the EC2 compute resources that you don’t use.

08 Repeat steps no. 4 – 7 to verify the CPU and memory usage data available in the last 7 days for the rest of the EC2 instances provisioned in the current region.

09 Change the AWS region from the navigation bar and repeat the audit process for other regions.

01 Run describe-instances command (OSX/Linux/UNIX) using necessary filtering to list the IDs of all active (running) EC2 instances provisioned in the selected region:

aws ec2 describe-instances
	--region us-east-1
	--filters Name=instance-state-name,Values=running
	--output table
	--query 'Reservations[*].Instances[*].InstanceId'

02 The command output should return a table with the requested instance IDs:

-------------------------
|   DescribeInstances   |
+-----------------------+
|  i-05fcff864132bd9c5  |
|  i-03a5346e06d942b47  |
|  i-0bd4dfa00d01f7c19  |
+-----------------------+

03 Run get-metric-statistics command (OSX/Linux/UNIX) to get the statistics recorded by AWS CloudWatch for the CPUUtilization metric representing the CPU usage of the selected EC2 instance. The following command example returns the average CPU utilization for an EC2 instance identified by the ID i-05fcff864132bd9c5, usage data captured during a 7-day time frame, using a time interval of 1 hour as the granularity for the returned datapoints:

aws cloudwatch get-metric-statistics
	--region us-east-1
	--metric-name CPUUtilization
	--start-time 2017-03-04T17:21:00
	--end-time 2017-03-11T17:21:00
	--period 3600
	--namespace AWS/EC2
	--statistics Average
	--dimensions Name=InstanceId,Value=i-05fcff864132bd9c5

04 The command output should return the CPU usage details requested:

{
    "Datapoints": [
        {
            "Timestamp": "2017-03-04T17:21:00Z",
            "Average": 3.2085,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-04T18:21:00Z",
            "Average": 4.033499999999999995,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-04T19:21:00Z",
            "Average": 1.10425,
            "Unit": "Percent"
        },

        ...

        {
            "Timestamp": "2017-03-11T15:21:00Z",
            "Average": 2.030999999999999993,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-11T16:21:00Z",
            "Average": 2.02833333333333333,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-11T17:21:00Z",
            "Average": 3.02783333333333333,
            "Unit": "Percent"
        }
    ],
    "Label": "CPUUtilization"
}

05 Determine the EC2 instance memory usage by querying the EC2MemoryUtilization metric data (or whatever name you have used for your custom metric) reported by the CloudWatch script installed on the selected EC2 instance (this rule assumes that the script has been successfully installed and it has recorded memory usage data within the past 7 days). To verify the instance memory usage reported by your custom CloudWatch metric, run get-metric-statistics command (OSX/Linux/UNIX) using the metric name as identifier. The following command example returns the average memory utilization for an EC2 instance identified by the ID i-05fcff864132bd9c5, from the usage data captured by a CloudWatch metric named EC2MemoryUtilization, during a 7-day time frame, using a time interval of 1 hour as the granularity for the returned datapoints:

aws cloudwatch get-metric-statistics
	--region us-east-1
	--metric-name EC2MemoryUtilization
	--start-time 2017-03-04T17:25:00
	--end-time 2017-03-11T17:25:00
	--period 3600
	--namespace AWS/EC2
	--statistics Average
	--dimensions Name=InstanceId,Value=i-05fcff864132bd9c5

06 The command output should return the memory usage details requested:

{
    "Datapoints": [
        {
            "Timestamp": "2017-03-04T17:25:00Z",
            "Average": 5.2085,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-04T18:25:00Z",
            "Average": 6.033499999999999995,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-04T19:25:00Z",
            "Average": 6.10425,
            "Unit": "Percent"
        },

        ...

        {
            "Timestamp": "2017-03-11T15:25:00Z",
            "Average": 9.030999999999999993,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-11T16:25:00Z",
            "Average": 9.02833333333333333,
            "Unit": "Percent"
        },
        {
            "Timestamp": "2017-03-11T17:25:00Z",
            "Average": 9.35783333333333333,
            "Unit": "Percent"
        }
    ],
    "Label": "EC2MemoryUtilization"
}

07 Repeat steps no. 3 – 6 to verify the required CPU and memory usage data for the rest of the EC2 instances available within the current region.

08 Change the AWS region by updating the --region command parameter value and repeat steps no. 1 - 7 to perform the entire audit process for other regions.

01 Sign in to the AWS Management Console.

02 Navigate to EC2 dashboard at https://console.aws.amazon.com/ec2/.

03 In the navigation panel, under INSTANCES section, choose Instances.

04 Select the underused EC2 instance that you want to resize (see Audit section part I to identify the right resource).

05 Click Actions button from the dashboard top menu, select Instance State, then select Stop.

06 Inside the Stop Instances dialog box, review the action details and click Yes, Stop to confirm the action.

07 Once the instance is stopped (i.e. Instance State set to stopped), use again the Actions button from the dashboard top menu, select Instance Settings, then select Change Instance Type.

08 In the Change Instance Type dialog box, perform the following:

1. From the Instance Type dropdown list, select the instance type to downsize to (e.g. c4.large – see EC2 Instance Types page available at this URL to help you choose the right instance type).
2. (Optional) Select EBS-optimized to enable EBS optimization or deselect EBS-optimized to disable EBS optimization. This feature provides dedicated throughput to your AWS EBS volumes for best I/O performance (additional charges apply).
3. Click Apply to resize the selected instance.

09 Now click Actions button from the dashboard top menu, select Instance State, then select Start.

10 In the Start Instances dialog box, click Yes, Start to restart the instance. Once the booting process is complete, the EC2 instance status should change from pending to running (this may take few minutes).

11 Repeat steps no. 4 - 10 to downsize (resize) any other underutilized EC2 instances provisioned in the current region.

12 Change the AWS region from the navigation bar and repeat the remediation process for other regions.

01 Run stop-instances command (OSX/Linux/UNIX) using the resource ID as identifier to stop the underused EC2 instance that you want to resize (see Audit section part II to identify the right instance):

aws ec2 stop-instances
	--region us-east-1
	--instance-ids i-05fcff864132bd9c5

02 The command output should return the stop request metadata:

{
    "StoppingInstances": [
        {
            "InstanceId": "i-05fcff864132bd9c5",
            "CurrentState": {
                "Code": 64,
                "Name": "stopping"
            },
            "PreviousState": {
                "Code": 16,
                "Name": "running"
            }
        }
    ]
}

03 Once the instance is stopped (should take one minute), run modify-instance-attribute command (OSX/Linux/UNIX) to resize the selected EC2 instance to the desired type. The following command example downsize an EC2 instance identified by the ID i-05fcff864132bd9c5 by resizing it from a c4.xlarge-type instance to a c4.large-type instance. If successful, no output is returned:

aws ec2 modify-instance-attribute
	--region us-east-1
	--instance-id i-05fcff864132bd9c5
	--instance-type "{\"Value\": \"c4.large\"}"

04 Run start-instances command (OSX/Linux/UNIX) to restart the EC2 instance resized at the previous step (it may take few minutes until the instance enters the running state):

aws ec2 start-instances
	--region us-east-1
	--instance-ids i-05fcff864132bd9c5

05 The command output should return the start request information:

{
    "StartingInstances": [
        {
            "InstanceId": "i-05fcff864132bd9c5",
            "CurrentState": {
                "Code": 0,
                "Name": "pending"
            },
            "PreviousState": {
                "Code": 80,
                "Name": "stopped"
            }
        }
    ]
}

06 Repeat steps no. 1 - 5 to downsize (resize) any other underused EC2 instances available within the current region.

07 Change the AWS region by updating the --region command parameter value and repeat the entire process for other regions.