What are the differences between Tibco EMS and Rendezvous
What are some of the key differences between these two technologies? Does one have obvious advantages over the other?
Answer
RV is like a radio broadcaster and EMS is like a telephone.
If you want to send a message to everyone in town (e.g. the weather forecast for today) then a radio is good because one message goes to everyone simultaneously. Telephone is bad because it takes a long time to call everyone and you pay 20c a call.
If you want to tell someone your credit card number you would use the telephone because you can be sure you are talking to the right person. Radio is bad because then everyone in town knows your credit card number.
RV uses a reliable multicast protocol so it supports fast high fan-out messaging capabilities like sending stock ticks to a large number of trading desks (what it was originally designed for). But the tradeoff is poor security and some limits on administration. There are also special considerations for communication across multiple LAN segments or WANs.
EMS is a JMS provider which communicates in a point-to-point fashion much like a telephone. Security is better and administration tasks are easier. EMS is server based (vs RV's peer-to-peer architecture) so store and forward type activities are easier than with RV.
You can mix and match the two to get the best of both worlds. I think later versions of EMS have a multicast capability for Topics, but I haven't used that.