infiniband: ?

[Andrew Tridgell]

Alexander,

 > This was what actually led me to suggest doing socket-like
 > interface to Peter, as we anyway will have TCP/IP version and code
 > sharing would be good enough.  In case this wouldn't fly most of
 > infrastructure work would still be in use by TCP/IP backend.

ok, though we will have to test to see if using a sockets like API
adds any latency. The CTDB protocol really wants a datagram style
interface, where the breaking up of the command stream into packets is
done below the ctdb code. On TCP I'll be faking that in the usual way,
but if IB can do it already then it would be nice not to lose that.

 > However, I would also like to see this done through SDP (sockets
 > direct protocol) as it bypasses TCP/IP overhead while maintaining
 > socket-compatible API. The reason for that is because Infiniband
 > itself is a reliable transport. May be going through SDP would be a
 > better thing?

I haven't looked at SDP yet, though I did come across a 2004 web page
saying that Microsoft claimed some rights to SDP, implying that it
might be patent encumbered. Can you and Pater check on the status of
that before you commit to SDP ?

Cheers, Tridge