Re: Did *bufferbloat* cause the 2010 flashcrash?

[Harlan Stenn <stenn () nwtime org>]

In 8/6/15 10:44 AM, William Herrin wrote:
> The intermediate cause of the problem was propagation delay (including
> buffer bloat) which induced an oscillating set of states in the
> trading software.
>
> The root cause was a flipping jassack trying to out-time his
> competitors by assuming a degree of instantaneity which proved untrue.
> Don't do that. Don't make assumptions about network timing. You can
> count on being wrong. If timing matters to your application, find a
> way to continuously measure.

Similar things happen when folks decide they are going to twiddle the
knobs of NTP's behavior.  NTP works locally, and gets/provides
information globally.  More or less.  When folks decide to make a change
in its core behavior, the usually don't consider how those changes will
affect anybody else.

I know enough about this to know I don't know anywhere near enough about
it, so I leave the knobs alone.

-- 
Harlan Stenn <stenn () nwtime org>
http://networktimefoundation.org - be a member!