So we all agree we need asynchronous, reliable, standard web services. Reliability is because applications, being pretty dumb, cannot cope, like human beings with http rather erratic semantics. Asynchronous because we know from EAI times that it is better. Standard because this is what Web Services are all about.
So is SOAP on JMS the solution? Partly yes because it is indeed asynchronous and with guaranteed once&onlyonce semantics Partly no because of 2 problems, one small (semantics mismatch) and one big (standard protocol) The small problem: the semantics problem is related to the fact that JMS embeds a model with queues (one to one messaging) and topics (publish and subscribe) This does not map so obviouly on SOAP+WSDL IMHO, it is very difficult to imagine that the programmer ignore he/she is using a queue or a topic, or defer that decision to deployment time as some seem to hope. As a consequence, there will be many ways to do the semantic mapping and they will not interoperate. The big problem JMS is only an API, not a protocol, and protocol implementations are proprietary So it is limited to the intranet. This is rather contradictory with the Web model where the same protocols are used inside and outside the firewall, with the nice lowering of costs attached to this standardisation. Looking now at Sonic's contribution: http://www.oetrends.com/cgi-bin/page_display.cgi?109 what exactly is Sonic/Apache proposing to solve this dilemna? and BTW what is delivered in Axis 1.0? is it only a client "SOAP/WSDL to JMS" binding or also the JMS MOM engine? If no engine, do you have to buy one, considering that open source JMS engines are not so popular, even if they exist (JORAM, SwiftMQ, activeJMS...)? Furthermore, it is pretty easy to design a quick and dirty JMS provider with none of the reliability of MQseries (or Sonic BTW :-) Now if we count SOAP on JMS out for B2B, what is proposed? Holt Adams from IBM proposes 4 patterns in: http://www-106.ibm.com/developerworks/webservices/library/ws-asynch1.html?dw zone=webservices Patterns 3 and 4 which can run on http are sort of toys IMHO I am not criticizing the proposal, but I do believe that any web service going beyond "get a quote" needs some semantic guarantees from the transport because it is VERY different to deal with a transport loosing one message out of 1000 and another one loosing one message out of 1 million; Pattern 3 is polling: back to 1960 ;-) can you imagine your mobile phone polling the network? Pattern 4 is "build your own MOM at the application level" which is TOO DIFFICULT for the "average programmer". So we are back to Patterns 1 and 2 which, unfortunately, have only one possible transport outside the firewall, httpr (unless of course you do no want reliability, back to toy applications) But httpr is only an IBM proposal, nothing like a standard for the time being Running into circles! Looks like we have no solution ... Now, some techno politic fiction .. what I believe is really happening behind the curtains: All the IBM and Microsoft technical luminaries have understood all of the above since at least one year. So they probably meet monthly in a nice wooden hotel in a Colorado ski resort to try to come up with a solution for the world. IBM is pushing a solution at transport level, httpr. Microsoft is pushing a WS-RM (reliable messaging) at the SOAP level. The problem is: how come the white smoke is not out already, is it so difficult to find a technical solution, are there more political issues that I cannot even imagine? Why is it that they managed to converge on WS-T and WS-C, which, IMHO, is something which is not really needed for the next 2 years, and that the more useful and better understood WS-RM convergence is not happening? There is no irony above, I do believe this duopolistic process is quite acceptable to move things forward, considering that W3C is going forward at a pretty low speed. Your opinion is welcome on the fictional aspect of the above ... Disclaimer: It is entirely possible that, from my remote french location, I cannot really see behind the curtains and as a consequence, my fairy tale can be entirely wrong, or I may have missed some key aspect ... The bottom line is that as a consultant, I would like to be able to tell my customers to use WS for serious business, but I honestly cannot. If we collectively do not solve the WS-RM issue in the next 12 months, WS will go down the Gartner hype curve at a very dangerous speed and our customers will label it as yet another techno fad. If you are still reading at this point, I can only thank you for yor patience :-) and hope for the best -- Jacques Talbot - Architecture Consultant - Teamlog 10 rue Lavoisier - 38330 Montbonnot T�l: +33 4 76 61 37 12 M�l: [EMAIL PROTECTED] T�l. mobile +33 6 07 83 42 00
