Provided by Black Web 2.0

Caffeine is a complete redesign of Google’s search index. While they reign as the #1 search engine, they have never been known to stop innovating. The web has changed and we have come to expect things to happen immediately. When we search, we want the most relevant and freshest results. When we publish things on the web, we want them to show up right now. Google has taken steps to make their search more realtime by integrating with the social web, but they have decided to go much further than that.

The results you see when you search Google come from their search index, which is a representation of the web as they see it stored in a database somewhere. Every so often, Google’s web crawlers go out and try to figure out what has changed. The web is now a rich ecosystem of data, going way beyond simple text and images, so this strategy doesn’t quite fit. It’s also slow to update. If you’ve ever published something and then waited and waited for it to show up in Google, you know how annoying that can be.

Caffeine lets us index web pages on an enormous scale. In fact, every second Caffeine processes hundreds of thousands of pages in parallel. If this were a pile of paper it would grow three miles taller every second. Caffeine takes up nearly 100 million gigabytes of storage in one database and adds new information at a rate of hundreds of thousands of gigabytes per day. You would need 625,000 of the largest iPods to store that much information; if these were stacked end-to-end they would go for more than 40 miles.

Caffeine is a fresh take on an old idea and should go a long way in keeping Google at the top of their search game. It’s also an investment in the future, providing a strong, scalable, and faster base for future developments in search. It seems that this is just the beginning. This back-end change should bring users some nice benefits on the front-end, making search more useful and relevant in the months ahead.

Official Google Blog Post:

Our new search index: Caffeine
6/08/2010 05:00:00 PM
(Cross-posted on the Webmaster Central Blog)

Today, we’re announcing the completion of a new web indexing system called Caffeine. Caffeine provides 50 percent fresher results for web searches than our last index, and it’s the largest collection of web content we’ve offered. Whether it’s a news story, a blog or a forum post, you can now find links to relevant content much sooner after it is published than was possible ever before.

Some background for those of you who don’t build search engines for a living like us: when you search Google, you’re not searching the live web. Instead you’re searching Google’s index of the web which, like the list in the back of a book, helps you pinpoint exactly the information you need. (Here’s a good explanation of how it all works.)

So why did we build a new search indexing system? Content on the web is blossoming. It’s growing not just in size and numbers but with the advent of video, images, news and real-time updates, the average webpage is richer and more complex. In addition, people’s expectations for search are higher than they used to be. Searchers want to find the latest relevant content and publishers expect to be found the instant they publish.

To keep up with the evolution of the web and to meet rising user expectations, we’ve built Caffeine. The image below illustrates how our old indexing system worked compared to Caffeine:

Our old index had several layers, some of which were refreshed at a faster rate than others; the main layer would update every couple of weeks. To refresh a layer of the old index, we would analyze the entire web, which meant there was a significant delay between when we found a page and made it available to you.

With Caffeine, we analyze the web in small portions and update our search index on a continuous basis, globally. As we find new pages, or new information on existing pages, we can add these straight to the index. That means you can find fresher information than ever before—no matter when or where it was published.

Caffeine lets us index web pages on an enormous scale. In fact, every second Caffeine processes hundreds of thousands of pages in parallel. If this were a pile of paper it would grow three miles taller every second. Caffeine takes up nearly 100 million gigabytes of storage in one database and adds new information at a rate of hundreds of thousands of gigabytes per day. You would need 625,000 of the largest iPods to store that much information; if these were stacked end-to-end they would go for more than 40 miles.

We’ve built Caffeine with the future in mind. Not only is it fresher, it’s a robust foundation that makes it possible for us to build an even faster and comprehensive search engine that scales with the growth of information online, and delivers even more relevant search results to you. So stay tuned, and look for more improvements in the months to come.