If we would just forget about discriminatory traffic management (e.g. based on deep packet inspection) life on the network would be pretty simple, even under overload conditions. A lot has been written about this already but Wes really nails it in his summary. Maximized profit, minimized frustration, everybody’s happy…

The 2007 Nobel prize in Physics has been awarded to Albert Fert and Peter Grünberg for independently discovering Giant Magnetoresistance in 1988. Their work had a tremendous impact on the computer industry as it revolutionized the way we could store and retrieve information on hard disks. It was the first major application of nanotechnology and allowed hard disks to shrink from the size of a large washing machine to the device that fits in an mp3 player.

There are two fascinating compilations on the nobelprize website that accompany the prize: a high level article titled “Information for the public” and a more detailed “Scientific Background on The Discovery of Giant Magnetoresistance”. Both are highly recommended readings.

The Institutional Yes is a Harvard Business Review interview with Jeff Bezos about the way strategies are developed at Amazon. I have written before about how the relentless customer focus translates into driving architecture and design using the “working backwards” approach. The interview with Jeff gives you more insight on the impact of customer focus on overall strategy and how it drives a culture of experimentation.

There is a fun quote at the end of article: “I always tell people that our culture is friendly and intense, but if push comes to shove, we’ll settle for intense”. Absolutely true. There is no lack of intensity at this company.

There is a lot of positive feedback about the Dynamo paper but I noticed that something I wrote in introducing the paper is being misunderstood. This was my fault, I wrote it too strongly.

What I meant by internal-only is that Dynamo is not directly exposed externally. However, Dynamo and similar Amazon technologies are used to power parts of our Amazon Web Services, such as S3. We are using these kinds of technologies to constantly improve the services we offer.

In two weeks we’ll present a paper on the Dynamo technology at SOSP, the prestigious biannual Operating Systems conference. Dynamo is internal technology developed at Amazon to address the need for an incrementally scalable, highly-available key-value storage system. The technology is designed to give its users the ability to trade-off cost, consistency, durability and performance, while maintaining high-availability.

Let me emphasize the internal technology part before it gets misunderstood: Dynamo is not directly exposed externally as a web service; however, Dynamo and similar Amazon technologies are used to power parts of our Amazon Web Services, such as S3.

We submitted the technology for publication in SOSP because many of the techniques used in Dynamo originate in the operating systems and distributed systems research of the past years; DHTs, consistent hashing, versioning, vector clocks, quorum, anti-entropy based recovery, etc. As far as I know Dynamo is the first production system to use the synthesis of all these techniques, and there are quite a few lessons learned from doing so. The paper is mainly about these lessons.

We are extremely fortunate that the paper was selected for publication in SOSP; only a very few true production systems have made it into the conference and as such it is a recognition of the quality of the work that went into building a real incrementally scalable storage system in which the most important properties can be appropriately configured.

Dynamo is representative of a lot of the work that we are doing at Amazon; we continuously develop cutting edge technologies using recent research, and in many cases do the research ourselves. Much of the engineering work at Amazon, whether it is in infrastructure, distributed systems, workflow, rendering, search, digital, similarities, supply chain, shipping or any of the other systems, is equally highly advanced.

The official reference for the paper is:

Giuseppe DeCandia, Deniz Hastorun, Madan Jampani, Gunavardhan Kakulapati, Avinash Lakshman, Alex Pilchin, Swami Sivasubramanian, Peter Vosshall and Werner Vogels, “Dynamo: Amazon's Highly Available Key-Value Store”, in the Proceedings of the 21st ACM Symposium on Operating Systems Principles, Stevenson, WA, October 2007.

A pdf version is available here. You can also read the full online version.

The text of the paper is copyright of the ACM and as such the following statement applies:

© ACM, 2007. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in SOSP’07, October 14–17, 2007, Stevenson, Washington, USA, Copyright 2007 ACM 978-1-59593-591-5/07/0010

Dynamo: Amazon’s Highly Available Key-value Store

Giuseppe DeCandia, Deniz Hastorun, Madan Jampani, Gunavardhan Kakulapati, Avinash Lakshman, Alex Pilchin, Swaminathan Sivasubramanian, Peter Vosshall and Werner Vogels

Amazon.com

Abstract

Reliability at massive scale is one of the biggest challenges we face at Amazon.com, one of the largest e-commerce operations in the world; even the slightest outage has significant financial consequences and impacts customer trust. The Amazon.com platform, which provides services for many web sites worldwide, is implemented on top of an infrastructure of tens of thousands of servers and network components located in many datacenters around the world. At this scale, small and large components fail continuously and the way persistent state is managed in the face of these failures drives the reliability and scalability of the software systems.

This paper presents the design and implementation of Dynamo, a highly available key-value storage system that some of Amazon’s core services use to provide an “always-on” experience.  To achieve this level of availability, Dynamo sacrifices consistency under certain failure scenarios. It makes extensive use of object versioning and application-assisted conflict resolution in a manner that provides a novel interface for developers to use.

Categories and Subject Descriptors
D.4.2 [Operating Systems]: Storage Management; D.4.5 [Operating Systems]: Reliability; D.4.2 [Operating Systems]: Performance;

General Terms
Algorithms, Management, Measurement, Performance, Design, Reliability.

My old friend Steve Vinoski is back online. Steve was with Iona for many, many years, working as the main architect on many of their Middleware technologies. Steve left Iona this spring to work for a start-up in the Boston area.

But Steve became really famous for this drawing, which he used to express his opinion about my keynote at Middleware 2004. He had borrowed my tablet and delivered this masterpiece during the panel that followed.