Re: [Cerowrt-devel] Fwd: Dave's wishlist [was: Source-specific routing merged]

[David Lang <david@lang.hm>]

On Tue, 17 Mar 2015, Dave Taht wrote:

> My quest is always for an extra "9" of reliability. Anyplace where you can
> make something more robust (even if it is out at the .9999999999) level, I
> tend to like to do in order to have the highest MTBF possible in
> combination with all the other moving parts on the spacecraft (spaceship
> earth).

There are different ways to add reliability

one is to try and make sure nothing ever fails

the second is to have a way of recovering when things go wrong.


Bufferbloat came about because people got trapped into the first mode of 
thinking (packets should never get lost), when the right answer ended up being 
to realize that we have a recovery method and use it.

Sometimes trying to make sure nothing ever fails adds a lot of complexity to the 
code to handle all the corner cases, and the overall reliability will improve by 
instead simplify normal flow, even if it add a small number of failures, if that 
means that you can have a common set of recovery code that's well excercised and 
tested.

As you are talking about loosing packets with route changes, watch out that you 
don't fall into this trap.

David Lang