The thing we're most proud of is the "instant" in Instant Domain Search - our searches are so fast, we can perform them as you type the name you want to look up. Today we're excited to announce our new distributed searching infrastructure. We now have search servers in Europe and Asia to minimize the transoceanic network lag that our users experience when searching for available domain names.
How it works
The new version of Instant Domain Search runs on Amazon's EC2 cloud computing server. The main web site is hosted on a central app server in the us-east-1 region (located in Virginia). When you load the home page, it's given a list of search servers it can use to look up domain names. By default it's configured to use the search server running next to the main appserver in Virginia. When the search page loads, it does some test searches on each server, verifying that they're working properly, and measuring how long it takes each server to respond. Once it's collected enough data, it selects the server that's giving the fastest responses, and uses that for any queries that the user types into the search box. As the user does queries, the page is constantly re-evaluating the performance of the server it's using, and if that server slows down, it will switch over to another server to get the best performance it can.
We noticed that many of our users will do dozens or hundreds of queries in a single visit to the search page, and so we can get a lot of benefit by doing our performance measurement and optimization in the browser. Here's how it breaks down:
So 47% of our users find that the default search server in Virginia is fastest for them, and so get no benefit by switching to another one. Another 27% were presumably located somewhere on the West Coast, and saw almost 27% improvement by using the search server in California. We have fewer user in Europe and Asia, but they had slightly better performance improvements from using local search servers.
Overall, 53% of our users saw their queries speedup by an average of 27%.
Another benefit of this arrangment is automatic failover in case of a network outage or server failure. If a server does't answer at all, the search page doesn't send it any more searches. This has already worked out well for us. Just a few days ago, the machine hosting our Virginia search server failed, and all the queries transparently migrated over to the California server. We don't think any of our users even noticed. Client-side load balancing for the win!