[Spread-users] Re: [Spread-users]: Max time delivery?
jesus at omniti.com
Fri May 17 14:48:12 EDT 2002
Jonathan Stanton wrote:
>An interesting problem that occurs with this type of feature is that it is
>not clear in a distributed system who's clock represents 'real' time. If
>one clock is slow and so the message is marked as being sent an hour ago,
>should it be discarded immediately upon reaching another machine?
My two cents... partially unrelated. Clocks being out of sync? Not
Spread's problem. I think it is safe for any application to rely on
the system clocks of its cluster being in sync to the nearest 100ms or
so... It is a solved problem. "It's NTPs responsibility... not Spread's".
As for having this feature in spread: I guess I can see the advantage
of doing this in the daemon, because the user doesn't need to get the
message and then discard it, but aside from that, it is trivial to
implement this at the application level. Unless there is a really
compelling reason to implement this in Spread (like reducing network
traffic tremendouly because you have many non-local clients and many
late messages, then I think it should be handled in the app -- it is
much more flexible.
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