[erlang-questions] auto-syncing mnesia after a network split

David Mercer <>
Tue Dec 2 22:30:36 CET 2008


On Tuesday, December 02, 2008, Joel Reymont wrote:

> On Dec 2, 2008, at 8:24 PM, David Mercer wrote:
> 
> > How do you handle unsynched clocks on the two nodes?
> 
> I don't know. Should they go out of sync during the split if the split
> is short?

Aren't clocks always out of synch?  I thought it was impossible to perfectly
synch clocks due to signal transmission times, at least over a standard
network.  Even if the clocks were precisely in-synch, same problem if the
same transaction is received by the two nodes a microsecond apart: they'll
have different timestamps.  I wonder if adding some sort of GUID would solve
the problem...  Maybe a client-generated ID.

Another thought is that two transactions can be received by different nodes
in different order, resulting in different vnums for the same transactions
on different nodes.

Cheers,

David.





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