EC2 : Java Glossary

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Amazon offers a cloud hosting service called EC2 (Amazon Elastic Compute Cloud). You can run a Java Servlet womb on it or various other software. Your app floats around in the cloud of servers, growing and shrinking its resource usage depending on the load. You have your own virtual machine, so you can run pretty well any OS (Operating System) or application software your please. Nothing you do will crash anyone else’s virtual machine. It is like having your own dedicated server. EC2 is free for the first year for small sites. Thereafter, for small sites it is an hour. That would be $43.20 USD a month if you run your VM 24/7.

Load Sharing

This idea is you might run 1 to N servers at any one time, depending on the load. Unlike physical servers, you don’t need to pay for your virtual servers unless you are actively using them. My own site gets significant hits from North America, India, Russia and Europe. There is really no time I could safely shut my VM down entirely. But even a pair of virtual servers will cost less than a dedicated physical server.

One advantage is up time. If one of the server farm computers fails, your app on its virtual machine quickly moves to another. You don’t have to wait for your dedicated server to be repaired.

The disadvantage is, if you have unexpected very heavy load, I suspect you are on the hook to pay for it. There may be ways to limit your liability. I did not study the massive amount of documentation.

Pricing is very complicated. There are several books on how to reduce your bill.


EC2 (Amazon Elastic Compute Cloud)

FPS (Amazon Flexible Payments System)

S3 (Amazon Simple Storage Service)

SQS (Amazon Simple Queue Service)

SimpleDB is a distributed database.

CDN (Content Delivery Network)

IaaS (Infrastructure as a Service)

PaaS (Platform as a Service)

SaaS (Software as a Service)

Languages Supported by the API (Application Programming Interface)


Many of the books about EC2 do not have ISBNs (International Standard Book Numbers) and come only in Kindle format and are available only from You will have to buy a Kindle just to read them.

I discovered from my use of Amazon AWS (Amazon Web Services), that Amazon is dreadful about keeping documentation up to date. Nearly all my problems came from believing obsolete documentation. I think it thus important to find third party docs to help you sort anything to do with Amazon out.
book cover recommend book⇒Host Your Web Site In The Cloud: Amazon Web Services Made Easy: Amazon EC2 Made Easyto book home
by Jeff Barr 978-0-9805768-3-2 paperback
publisher SitePoint 978-1-4571-9159-6 eBook
published 2010-09-28 B0046ZRKZ8 kindle

It is hard to find recent books on EC2 and Amazon. It has been an unusually volatile API so you really want something published in the last six months. The book aims to:

  • gain a thorough understanding of cloud computing.
  • master the fundamentals of Amazon Web Services.
  • install and configure visual and command line tools.
  • store, retrieve and distribute data quickly and easily.
  • build applications that scale.
  • manage the monitoring, load balancing and scaling capabilities of cloud computing.
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Greyed out stores probably do not have the item in stock. Try looking for it with a bookfinder.
electronic product image recommend electronic⇒Ezio Time-based 6-Digit Token for use with Amazon Web Servicesto electronic home
asin B002CRN5X8
This product is not in stock at any of the Amazon stores.

Think about how this device might work: A high security implementation might works like this:

  • It has a private key burned into its firmware.
  • It encrypts the current time (rounded to the nearest 30 seconds) with the private key.
  • Amazon has on file a copy of the corresponding non-secret public key.
  • Amazon then takes the encrypted times, decrypts it with your public key and sees if it matches the current time.

The advantages include:

  • If someone snoops on your conversation, the password that they steal will not be of any use in future.
  • If someone breaks into Amazon, all they can steal is your public key which is non even a secret. It is useless for impersonating you.
  • If someone breaks into your computer, your private key is not there in any form. It lives only inside the token and cannot be retrieved.

A low security implementation might work like this:

  • To get it started, Amazon sends it a random number over and https: link.
  • The fob encrypts the current time (rounded to the nearest 30 seconds) with that seed.
  • Amazon has on file a copy of the corresponding seed.
  • Amazon then takes current time on its server, encrypts it to see if it matches the value just sent from the fob.

The weakness of this system, is if hackers steal the seeds, the whole system is compromised. The other weakness is that every website you use this device on, has to know its secret seed. That increase the odds of the hackers getting access to everything.


Manufacturers are notoriously close-lipped about just how their devices work. They don’t want you to crack them or be aware of their vulnerabilities to help protect yourself. However, they say they implement OATH standards, so that may contain a clue.

It is too bad that you cannot use this wonderful device on websites other than Amazan AWS, such as your bank.

A similar device could be invented that did not require you to key the generated password. You would insert it into a USB port. It would not even need a clock. Amazon could send a random string to encrypt. However, that hypothetical certificate-based device would need a special browser adaptation.

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EC2 pricing
ISP Vendors
RightScale: tool to help manage scaling up a large application

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