For TCP…
“We experiment with another configuration using TCP/IP and show that current J2EE application server clusters up to 16 nodes (the largest configuration we tested) can scale much better with this configuration.
We attribute the superiority of TCP/IP based group communications over UDP/IP multicast to a better flow control management and a better usage of the network switches available in cluster environments.”
And UDP..
“Having to support reliable multicast UDP communication is not a piece of cake. Drop a couple of packets and you get only a fraction of the throughput. Then lose the ordering of the packets and you are in a slump. The situation can turn pretty sour if you use large messages that get fragmented (more than one UDP packet). You only need to lose one packet to lose your entire message - then you resend everything. The point is that in unideal and congested conditions you start to miss TCP, and it is probably extremely hard to beat its adaptive protocol that has been perfected for so many years.”
I would also like to know if any companies out there make the change from UDP to TCP and if they can share their experience with us.
Thanks
M. Wagad.