Facebook Interview Question: Why wouldn't you want a root ... | Glassdoor

Interview Question

Production Engineer Interview Menlo Park, CA

Why wouldn't you want a root DNS server to answer queries

  for you, instead of delegating you to an authoritative server?

Interview Answer

4 Answers


Answering queries would be a lot more overhead for the root DNS server, and think about the amount of DNS queries it gets.. load balancing

Anonymous on Apr 8, 2013

Because root DNS server can't handle zillions of requests at once, that's why you need a load balancer to split tasks on multiple DNS servers. every server has it's own limits, and load balancing helps to "scale" the limits.

holms on Aug 19, 2013

because it would be faster due also to caching mechanism.

Giorgio on Oct 30, 2013

DNS servers basically are text file doing Name to IP mapping(A type).
So if a root server had to answer all the queries ,it would essentially be a million line text file, mapping each and every website.This would result in large CPU processing and time.
Essentially, Root servers redirect the query to top level DNS servers and so on

Anonymous on Apr 4, 2016

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