User guide

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To request a Spot Instance, you simply need to build your request with the parameters we have specified

so far. We start by creating a RequestSpotInstanceRequest object.The request object requires the

number of instances you want to start (2) and the bid price ($0.03). Additionally, you need to set the

LaunchSpecification for the request, which includes the instance type, AMI ID, and security group

you want to use. Once the request is populated, you call the requestSpotInstances method on the

AmazonEC2Client object. An example of how to request a Spot Instance is shown below.

1 RequestSpotInstancesRequest requestRequest = new RequestSpotInstances

Request();

requestRequest.SpotPrice = "0.03";

requestRequest.InstanceCount = 2;

LaunchSpecification launchSpecification = new LaunchSpecification();

launchSpecification.ImageId = "ami-fbf93092"; // latest Windows AMI as

of this writing

launchSpecification.InstanceType = "t1.micro";

10 launchSpecification.SecurityGroup.Add("GettingStartedGroup");

requestRequest.LaunchSpecification = launchSpecification;

RequestSpotInstancesResponse requestResult = ec2.RequestSpotInstances(re

questRequest);

There are other options you can use to configure your Spot Requests.To learn more, see RequestSpot-

Instances in the AWS SDK for .NET.

Running this code will launch a new Spot Instance Request.

Note

You will be charged for any Spot Instances that are actually launched, so make sure that you

cancel any requests and terminate any instances you launch to reduce any associated fees.

Step 4: Determining the State of Your Spot Request

Next, we want to create code to wait until the Spot Request reaches the "active" state before proceeding

to the last step. To determine the state of our Spot Request, we poll the describeSpotInstanceRequests

method for the state of the Spot Request ID we want to monitor.

The request ID created in Step 2 is embedded in the result of our requestSpotInstances request.

The following example code gathers request IDs from the requestSpotInstances result and uses

them to populate the SpotInstanceRequestId member of a describeRequest object. We will use

this object in the next part of the sample.

1 // Call the RequestSpotInstance API.

RequestSpotInstancesResponse requestResult = ec2.RequestSpotInstances(re

questRequest);

// Create the describeRequest object with all of the request ids

5 // to monitor (e.g. that we started).

DescribeSpotInstanceRequestsRequest describeRequest = new DescribeSpotIn

stanceRequestsRequest();

foreach (SpotInstanceRequest spotInstanceRequest in requestResult.Request

SpotInstancesResult.SpotInstanceRequest)

{

Version v2.0.0

AWS SDK for .NET Developer Guide

Step 4: Determining the State of Your Spot Request