using virtual synchrony for CTDB

[David Boreham]

Steven Dake wrote:

>I have a suggestion to use virtual synchrony for the transport mechanism
>of CTDB.  I think you will find using something like TCPIP unsuitable
>for a variety of reasons.
>  
>
I'm very far from being a VS expert, but when I looked into a few
of the open source implementations available a while back it became
clear (to me at least) that they have a kind of 'snake oil' property
in that they appear to deliver magical services but do so only by
using quite inefficient methods underneath the covers. For example
it appears that one is avoiding network round-trips but in fact to 
implement its
delivery guarantees the message middleware layer needs to propagate a token
around the set of participating nodes which of course involves many 
sends and
receives.