[CST-2] Distributed systems

[William R Sowerbutts]

On Sat, Jun 02, 2001 at 05:53:53PM +0100, Andrei Legostaev wrote:
>There seems to be an obvious problem with all distributed updates:
>
>How do we tell whether a failure is at the host or at the link?  If we can't
>tell then, for example, a host whose ethernet connector fell out with think
>that "Everybody's Dead, Dave" and proceed to make updates to itself.

Use heartbeat messages.


>Was this problem addressed anywhere in the lectures/notes (perhaps we made
>some assumption by which we don't have to worry about this)?

She glossed over it. To be fair, how it should be handled is probably quite
frequently application-specific.

Especially irritating are notes like "Two-phase commit can't handle this;
Three-phase commit can" and then no explanation of how. Grrrrr!


Will

_________________________________________________________________________
William R Sowerbutts (BtG)                            will@sowerbutts.com
Coder / Guru / Nrrrd                                http://sowerbutts.com
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