On Tue, 2012-05-08 at 15:42 -0400, Tom Horsley wrote:
On Tue, 08 May 2012 15:09:31 -0430
Patrick O'Callaghan wrote:
> I think it was Lamport
> who said that you can't tell 'down' from 'disconnected' (did the
remote
> server crash, or is there a network disconnection? maybe the network is
> just congested, there's no way to tell).
I can tell: If I've been getting responses in under 20 ms and now I
haven't gotten a response in 2 minutes, then the dadgum thing
is down :-).
Or some router along the way is down, or congested. You simply don't
know. Often you don't care, but sometimes you do because it makes a real
difference (e.g. distributed database transactions) so you have to
program defensively. However reliability is not cheap and is never
perfect.
poc