Re: Persistence

[Jonathan S. Shapiro]

On Mon, 2005-10-31 at 02:45 +0100, R. Koot wrote:
> When I first read about persistance in EROS I though it was great, but 
> there is still the problem that after a crash you are transported back 
> in time. Doesn't this create more troubles than it solves? Especially in 
> networked environments. I'm think about the case where my 'files' are 
> stored on another computer, in particular. I also read EROS/KesKOS allow 
> programs to force a snapshot, if this happens frequently doesn't this 
> greatly reduce performance?

Persistence stops at the machine boundary. The difficulties of network
recovery after a crash are no better or worse than for any other system.

Yes, there exists a mechanism that allows certain applications to demand
a checkpoint now. This mechanism is considered sensitive, and it is NOT
available to applications in general. It is used by things like database
systems and system installers.

shap