User guide

Tutorial: Amazon EC2 Spot Instances
Overview
Spot Instances allow you to bid on unused Amazon Elastic Compute Cloud (Amazon EC2) capacity and
run the acquired instances for as long as your bid exceeds the current Spot Price. Amazon EC2 changes
the Spot Price periodically based on supply and demand, and customers whose bids meet or exceed it
gain access to the available Spot Instances. Like On-Demand Instances and Reserved Instances, Spot
Instances provide you another option for obtaining more compute capacity.
Spot Instances can significantly lower your Amazon EC2 costs for batch processing, scientific research,
image processing, video encoding, data and web crawling, financial analysis, and testing. Additionally,
Spot Instances give you access to large amounts of additional capacity in situations where the need for
that capacity is not urgent.
To use Spot Instances, place a Spot Instance request specifying the maximum price you are willing to
pay per instance hour; this is your bid. If your bid exceeds the current Spot Price, your request is fulfilled
and your instances will run until either you choose to terminate them or the Spot Price increases above
your bid (whichever is sooner).
It's important to note two points:
• You will often pay less per hour than your bid. Amazon EC2 adjusts the Spot Price periodically as
requests come in and available supply changes. Everyone pays the same Spot Price for that period
regardless of whether their bid was higher. Therefore, you might pay less than your bid, but you will
never pay more than your bid.
• If you're running Spot Instances and your bid no longer meets or exceeds the current Spot Price, your
instances will be terminated. This means that you will want to make sure that your workloads and
applications are flexible enough to take advantage of this opportunistic capacity.
Spot Instances perform exactly like other Amazon EC2 instances while running, and like other Amazon
EC2 instances, Spot Instances can be terminated when you no longer need them. If you terminate your
instance, you pay for any partial hour used (as you would for On-Demand or Reserved Instances).
However, if the Spot Price goes above your bid and your instance is terminated by Amazon EC2, you
will not be charged for any partial hour of usage.
This tutorial provides a quick overview of how to use the Java programming language to do the following.
• Submit a Spot Request
• Determine when the Spot Request becomes fulfilled
• Cancel the Spot Request
• Terminate associated instances
Prerequisites
To use this tutorial you need to be signed up for Amazon Web Services (AWS). If you have not yet signed
up for AWS, go to the Amazon Web Services website, and click Create an AWS Account in the upper
right corner of the page. In addition, you also need to install the AWS Java SDK.
If you are using the Eclipse development environment, we recommend that you install the AWS Toolkit
for Eclipse. Note that the AWS Toolkit for Eclipse includes the latest version of the AWS SDK for Java.
Version v1.0.0
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AWS SDK for Java Developer Guide
Tutorial: Amazon EC2 Spot Instances