Q: It’s amazing how fast Google can process search queries and deliver the results to my screen. How do they do it!?
Google searches have become so ingrained into our everyday lives that it’s easy to take for granted how amazing they really are.
No matter what you type in the search box, Google is able to query the billions and billions of webpages it has indexed and present a list of the most relevant results, seemingly instantly.
But your Google search actually embarks on a rather long journey during those milliseconds, involving many connected machines.
While many of the technical details are beyond the scope of this post (we plan to have a more comprehensive series of How Google Works in the future), the basics are still quite fascinating.
First of all, Google owns a staggering number of machines, estimated to be in the hundreds of thousands, which are located in many different datacenters around the world. These computers work together to help perform your searches.
When you hit the “search” button, your query gets sent to a particular cluster of thousands of computers. Each individual computer only contains a small fraction of the index, but together, they represent everything on the web that Google has crawled.
Your search terms are passed on to each of these computers simultaneously, which return a list of matches from their part of the index. Then the results from the individual machines are merged together and ranked according to Google’s search algorithm.
This combined list of results then gets sent back to your computer screen, just about a tenth of a second after you hit the search button.
A 2009 blog post reported that a single Google query uses 1000 Machines in 0.2 seconds, which is likely an even higher number today.
The Google search interface maybe be ridiculously simple to use, but don’t forget that there is an awful lot going on under the hood.