[OpenAFS-devel] N800, Mobile AFS, and changing IP addresses

[Derrick Brashear]

> >
> > > Tune the AFS timeouts so that the user get's failure messages more
> > > quickly?
> > >
> >
>
>  If by "tune the AFS timeouts" you mean "make them smaller", don't do that.

The right thing to do is to use the network stack to notice, if at all
possible, that you have no network.

> It is tempting to lower timeouts to reduce the amount of time you have to
> wait when something isn't working, assuming that when it is working you'll
> get a response quickly because it seems that way every time you look.  But
> most people haven't seen a wide enough variety of networks to make this
> generalization; a "short" timeout that works for you may not work so well
> for someone with a high-latency path or a heavily-loaded server, and setting
> timeouts a bit too short means more and more frequent retransmissions, which
> can make a bad situation (heavy congestion) worse.

 []

>  It seems the simplest thing to do here is whenever an interface is brought
> up to reset the state of all servers to "up".  This results in a fast
> response time for a server that really is up, at the expense of an extra
> timeout in cases where the user touches a server that is down before the CM
> gets around to doing the next 5 minute check.
>

I agree.