using virtual synchrony for CTDB

[Steven Dake]

On Fri, 2006-10-06 at 14:05 -0700, Tracy Camp wrote:
> Okay so you might not saturate your ethernet as fast with VS, but you also 
> wouldn't get as many messages on the wire with VS becaue you can't 
> transmit until you have the token, which in this case would seem to mean 
> N-1 nodes more latency.
> 
> t.
> 

This comparison of throughput and latency is confusing.  I'm not sure
what kind of latency you are speaking about.

In raw throughput terms, vs can deliver approx 40k messages per second
and does indeed saturate a GIGe network, whereas (over a switched
network) point to point can handle 1600 exchanges per second between two
nodes.  This scales to multiples of 1600 between multiple nodes
depending on switch bandwidth availability.