Amazon Web Services Developer Connection : Building a Web Applic. Eventual Consistency by Example. Recently, there has been a lot of chitchat about the eventual consistency model as illustrated in the famous Amazon Dynamo paper, and today employed by several non-relational databases such as Voldemort or Cassandra.Everything starts with this blog post by the Facebook Infrastructure Lead, claiming: "Dynamo: A flawed architecture", where he makes a few points against the eventual consistency model and the related "sloppy" quorum approach. However, his points seems to be based on a few misconceptions which the Amazon paper doesn't help to clarify, so let's try to spread some light by first giving a few definitions, and then a simple example. Definitions. We may sum up the eventual consistency model in the following statement: More specifically, values for N, W and R can be tuned in order to: An example. Let me show you the simplest possible example: a cluster of two nodes.
We have: Even easier: consistent reads are guaranteed by the W value equal to the replication factor. Finally ... See you! Jeff Bezos on the next web innovation. Typica - Project Hosting on Google Code. This is a simple API to access Amazon's SQS, EC2, CloudWatch, AutoScaling, ELB, SimpleDB, SNS, FPS and DevPay LS web services. It uses the QUERY APIs. This code is thread-safe and works very reliably to the best of my knowledge.
I've been using it on a system where sending messages in SQS is critical and we manage pools of servers on EC2. Typica has been tested with the Eucalyptus Community Cloud ( NOTE: The 1.7 release brings support for HttpClient 4, which means a change to the dependencies. How are you using typica? There is a new tool available for downloads. Dependencies: The combination of EC2, S3 and SQS is very compelling for building scalable applications. This project is referenced at the AWS Developer's Connection: The name (TIP-ik-uh) was chosen because this is a coffee grown in Brazil, through which the Amazon flows. Get your "typica" mug here! S3Map. Management and incentives at Google.
Jeff Bezos' Risky Bet. It was one of the Web's typical flash frenzies, a gaggle of geeks seeking the new, new thing. At 2 a.m. on Aug. 24, a new venture called Elastic Compute Cloud quietly launched in test mode. Its service: cheap, raw computing power that could be tapped on demand over the Internet just like electricity. In less than five hours, hundreds of programmers, hoping to use the service to power their MySpace (NWS) and Google (GOOG) wannabes, snapped up all the test slots. One desperate latecomer instant-messaged a $10,000 offer for a slot to a lucky winner, who declined to give it up. "It's really cool," enthuses entrepreneur Luke Matkins, who will run his soon-to-launch music site on the service. The creator of this très cool service: Amazon.com Inc. Yes, Amazon founder and Chief Executive Jeffrey P.
Slide Show >> Bezos wants Amazon to run your business, at least the messy technical and logistical parts of it, using those same technologies and operations that power his $10 billion online store. Amazon Web Services Developer Connection : Amazon Elastic Comput. Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides resizable compute capacity in the cloud. It is designed to make web-scale computing easier for developers. Amazon EC2’s simple web service interface allows you to obtain and configure capacity with minimal friction. It provides you with complete control of your computing resources and lets you run on Amazon’s proven computing environment.
Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change. Amazon EC2 changes the economics of computing by allowing you to pay only for capacity that you actually use. Amazon EC2 provides developers the tools to build failure resilient applications and isolate themselves from common failure scenarios. Introduction to Amazon EC2 (4:01) Amazon EC2 enables you to increase or decrease capacity within minutes, not hours or days.
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