Using Auto Scaling to Launch Spot Instances

Launch configuration name = spotlc-5cents

Image ID = ami-e565ba8c

If you don't have an AMI, and you want to find a suitable one, see Amazon Machine Images (AMIs).

Instance type = m1.small

Spot price = $0.05

Auto Scaling Group name = spotasg

Launch configuration name = spotlc-5cents

Availability Zone = us-east-1a,us-east-1b

Max size = 5

Min size = 1

Desired capacity = 3

Check whether Auto Scaling is submitting your bids successfully.

The as-describe-scaling-activities command is a useful tool for this task. The command lists the activities that Auto Scaling performed for a specified Auto Scaling group.

This is the basic syntax:

as-describe-scaling-activities [ActivityIds [ActivityIds ...]] [--auto-scaling-group value] [--max-records value] [General Options]

Specifying the Auto Scaling group and the Activity ID is optional. Activity ID is an identifier for an Auto Scaling activity.

If you don't specify the Auto Scaling group, the command will return all activities for all Auto Scaling groups associated with your account. If you specify the Auto Scaling group, only the activities for that Auto Scaling group will be listed.

In this walkthrough, we are using the as-describe-scaling-activities command to see the state of your bid. Your command should look like the following example:

as-describe-scaling-activities --auto-scaling-group spotasg --headers

If not all your bids are fulfilled, you will get information that looks like the following example:

ACTIVITY  ACTIVITY-ID                           END-TIME              GROUP-NAME      CODE                      MESSAGE
ACTIVITY  31bcbb67-7f50-4b88-ae7e-e564a8c80a90                        spotasg         WaitingForSpotInstanceId  Placed Spot instance request: sir-fc8a3014. Waiting for instance(s)
ACTIVITY  770bbeb5-407c-404c-a826-856f65db1c57                        spotasg         WaitingForSpotInstanceId  Placed Spot instance request: sir-69101014. Waiting for instance(s)
ACTIVITY  597e4ebd-220e-42bc-8ac9-2bae4d20b8d7  2012-05-23T17:40:22Z  spotasg         Successful                                                                                   

In this response, you know that your bids were placed, one of the bids is successful, and Auto Scaling is waiting for the other two bids.

If you run the as-describe-scaling-activities command again later, you can be getting information that is similar to the following example:

ACTIVITY  ACTIVITY-ID                           END-TIME              GROUP-NAME      CODE      
ACTIVITY  90630906-b40f-41a6-967a-cd6534b2dfca  2012-06-01T02:32:15Z  spotasg         Successful
ACTIVITY  a1139948-ad0c-4600-9efe-9dab8ce23615  2012-06-01T00:48:02Z  spotasg         Successful
ACTIVITY  33001e70-6659-4494-a817-674d1b7a2f58  2012-06-01T02:31:11Z  spotasg         Successful

The output shows that the listed activities were successful. Because we know that spotasg is an Auto Scaling group that uses a launch configuration with a Spot bid price, you can assume that the activities represent the bids placed by Auto Scaling.

Find out more information about a scaling activity.

You can get more details about the activities and instances by using the --show-xml option of as-describe-scaling-activities. Your command should look like the following example:

as-describe-scaling-activities --auto-scaling-group spotasg --show-xml

The information you get should be similar to the following example:

<DescribeScalingActivitiesResponse xmlns="http://autoscaling.amazonaws.com/doc/2011-01-01/">
  <DescribeScalingActivitiesResult>
    <NextToken>b5a3b43e-10c6-4b61-8e41-2756db1fb8f5</NextToken>
    <Activities>
      <member>
        <StatusCode>Successful</StatusCode>
        <Progress>0</Progress>
        <ActivityId>90630906-b40f-41a6-967a-cd6534b2dfca</ActivityId>
        <StartTime>2012-06-01T00:48:21.942Z</StartTime>
        <AutoScalingGroupName>spotasg</AutoScalingGroupName>
        <Cause>At 2012-06-01T00:48:21Z a difference between desired and actual capacity changing the desired capacity, increasing the capacity from 2 to 3.</Cause>
        <Details>{}</Details>
        <Description>Launching a new EC2 instance: i-fe30d187</Description>
        <EndTime>2012-06-01T02:32:15Z</EndTime>
      </member>
      <member>
        <StatusCode>Successful</StatusCode>
        <Progress>0</Progress>
        <ActivityId>a1139948-ad0c-4600-9efe-9dab8ce23615</ActivityId>
        <StartTime>2012-06-01T00:47:51.293Z</StartTime>
        <AutoScalingGroupName>spotasg</AutoScalingGroupName>
        <Cause>At 2012-06-01T00:47:51Z an instance was taken out of service in response to a system health-check.</Cause>
        <Details>{}</Details>
        <Description>Terminating EC2 instance: i-88ce28f1</Description>
        <EndTime>2012-06-01T00:48:02Z</EndTime>
      </member>
      <member>
        <StatusCode>Successful</StatusCode>
        <Progress>0</Progress>
        <ActivityId>33001e70-6659-4494-a817-674d1b7a2f58</ActivityId>
        <StartTime>2012-06-01T00:46:19.723Z</StartTime>
        <AutoScalingGroupName>spotasg</AutoScalingGroupName>
        <Cause>At 2012-06-01T00:46:19Z a difference between desired and actual capacity changing the desired capacity, increasing the capacity from 2 to 3.</Cause>
        <Details>{}</Details>
        <Description>Launching a new EC2 instance: i-2c30d155</Description>
        <EndTime>2012-06-01T02:31:11Z</EndTime>
      </member>
      ...
    </Activities>
  </DescribeScalingActivitiesResult>
  <ResponseMetadata>
    <RequestId>d02af4bc-ad8f-11e1-85db-83e1968c7d8d</RequestId>
  </ResponseMetadata>
</DescribeScalingActivitiesResponse>

The XML output shows more detail about the Spot and Auto Scaling activity.

Confirm that Auto Scaling is launching your Spot Instances according to your specifications.

To confirm that Auto Scaling is launching the instances you want in the Availability Zones you specified, use as-describe-auto-scaling-groups. The command will show details about the group and instances launched. For information about the as-describe-auto-scaling-groups command, see Verify Auto Scaling Group Creation.

This is the basic syntax:

as-describe-auto-scaling-groups [AutoScalingGroupNames [AutoScalingGroupNames...]] [--max-records value] [General Options]

Specify the --headers general option to show the column headers, which can make the information easier to read.

Your command should look like the following example:

as-describe-auto-scaling-groups spotasg --headers

The information you get should be similar to the following example.

AUTO-SCALING-GROUP  GROUP-NAME      LAUNCH-CONFIG  AVAILABILITY-ZONES     MIN-SIZE  MAX-SIZE  DESIRED-CAPACITY
AUTO-SCALING-GROUP  spotasg         spotlc-5cents  us-east-1b,us-east-1a  1         5         3               
INSTANCE  INSTANCE-ID  AVAILABILITY-ZONE  STATE      STATUS   LAUNCH-CONFIG
INSTANCE  i-2c30d155   us-east-1a         InService  Healthy  spotlc-5cents
INSTANCE  i-fe30d187   us-east-1a         InService  Healthy  spotlc-5cents
INSTANCE  i-c630d1bf   us-east-1a         InService  Healthy  spotlc-5cents

You can see that Auto Scaling launched 3 instances in us-east-1a, as you specified, and they are all running.

Get details about your Spot Instances.

In addition to using as-describe-auto-scaling-groups, you can find out details about the Spot Instances launched for you by Auto Scaling, by using the as-describe-auto-scaling-instances command.

This is the basic syntax:

as-describe-auto-scaling-instances [InstanceIds [InstanceIds ...]] [--max-records value] [General Options]

Specifying InstanceIds is optional. If you specify it, the command will return information about the instance, if it exists. If you don't specify InstanceIds, the command returns information about all instances associated with your Auto Scaling account.

In this walkthrough, we are assuming that you created one launch configuration and Auto Scaling group, and you want to find out details about all your Spot Instances.

Your command should look like the following example:

as-describe-auto-scaling-instances --headers

The information you get should be similar to the following example:

INSTANCE  INSTANCE-ID  GROUP-NAME      AVAILABILITY-ZONE  STATE      STATUS   LAUNCH-CONFIG
INSTANCE  i-2c30d155   spotasg         us-east-1a         InService  HEALTHY  spotlc-5cents
INSTANCE  i-c630d1bf   spotasg         us-east-1a         InService  HEALTHY  spotlc-5cents
INSTANCE  i-fe30d187   spotasg         us-east-1a         InService  HEALTHY  spotlc-5cents

An Amazon Resource Name (ARN), which you generate when you create an Amazon Simple Notification Service (Amazon SNS) topic. An endpoint, such as an email address, must be subscribed to the topic in order for the endpoint to receive messages published to the topic. For more information, see Create a Topic in the Amazon Simple Notification Service Getting Started Guide.

An Auto Scaling Group, which you created earlier in this walkthrough.

A notification configuration. You configure an Auto Scaling group to send notifications when specified events take place by calling the as-put-notification-configuration CLI command or the PutNotificationConfiguration API action. For more information about the command, go to PutNotificationConfiguration in the Auto Scaling API Reference.

A list of Auto Scaling notification types, which are events that will cause the notification to be sent.

Scheduled action name: as-spotbid-schedule

Auto Scaling group: spotasg

Start time: 2012-05-15T19:10:00Z

End time: 2012-05-15T19:15:00Z

Desired capacity:20

Auto Scaling group name = spotasg

Force delete (optional parameter) = --force-delete

Created a launch configuration that launched Spot Instances.

Created an Auto Scaling group.

Obtained information about your Auto Scaling group and instances.

Set up notifications.

Updated the bid price.

Scheduled spot requests.

Cleaned up.