DNS and Authorative Answers

Just had to debug a little issue with a domain that were not considered authorative from our DNS server. The SOA records were there as they should be, and it referred the correct name server in the SOA record. A bit of searching at Google later turned up the cause of the issue; the name server did not have an NS entry for the domain. To be considered authorative, a domain server has to provide an NS entry for the domain too. As I do DNS stuff only a couple of minutes each year, details like that happily slides away to the darkest corners of my mind.

So to sum it up: Get your SOA and your NS records straight, and you can be authorative all day long! Authorative like it’s 1999!

Randy Shoup on Lessons of Scaling eBay

InfoQ has an article about scaling ebay online written by Randy Shoup about some of the lessons they’ve learned over at eBay during the years when it comes to scaling one of the largest internet sites in the world. The article is a very interesting read, and I’ll sum up the seven main points:

  1. Partition by Function
  2. Split Horizontally
  3. Avoid Distributed Transactions
  4. Decouple Functions Asynchronously
  5. Move Processing To Asynchronous Flows
  6. Virtualize At All Levels
  7. Cache Appropriately