North American Network Operators Group

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Re: How to achieve application reliability

  • From: Sean Donelan
  • Date: Sun Dec 05 11:38:37 1999

On Sat, 04 December 1999, James Smith wrote:
> Our only alternative is to eliminate every single-point failure with stuff
> like high availability clustering, redundant feeds, battery backups,
> nuclear reactors, physical separate sites on different planets, etc. :-)
> (Pardon me, it's 2:00am and I'm getting punching)

If you are using Microsoft products in your nuclear reactor, its not going
to be very reliable.  They aren't designed for that purpose.

The tools exist to make very reliable network applications, but we can't
force people to use them.  So long as applications neglect to use the other
information provided by the network, they are going to be vulnerable to
single points of failure.

Multiple A records exist for a reason.  Even if you have high availability
clustering, redundant feeds, battery backups, multi-homing, multi-sites; if
you are depending on a single global network announcement there is nothing
to prevent another ISP from announcing the same prefix with a shorter AS
path length, and effectively blackholing your network.  For people with
ultra-high reliablility requirements, a /19 isn't the solution.