So ApacheCon Europe ‘06 has been on in the Burlington for the past few days )anyone wandering around Donnybrook/Leeson Street in the mornings/evenings over may have noticed a “geek increase”. It was a bit smaller than I expected but the quality of the content was superb if one bears in mind that these guys are doing this stuff part time (well, some of them!). The sessions I attended were all SOA/OSGi centric and all were worth attending, from an educational point of view. A very partial summary:

  • The OSGi/JSR#291/JSR#277 issue is still very much alive although some efforts are being made to try achieve some degree of compatibility by using a common subset of Manifest headers. However differences apparently already exist in the drafts (such as the version range specifier format used) It is pretty sad to see such open (or should I say JCP-closed) disregard for interoperability between two overlapping JSR. Both are due for delivery in Dolphin (Java 7), perhaps by then the whole Java platform will have been rendered unusable by the plethora of other overlapping JSRs and we (the users) will all have moved on to coding in Ruby.
    Actually, by then, it may not matter - OSGi seems to be gaining considerable traction. Tuesday afternoon had a whole afternoon of talks and discussion from Richard Hall (Felix), Peter Kriens (OSGi Alliance/aQute), Marcel Offermans (Luminis) and a round table discussion involving folks from Apache Maven, Felix, Harmony, Directory Server projects. It seems some efforts are being made to try get Apache Jakarta projects to OSGi-fy their Manifests (via capabilities built into Maven)
  • Woden looks good. It’ll be the WSDL2.0 processor that all Java folks end up using (if you need to parse WSDL2.0 that is!). It replaces WSDL4J which is being put out to pasture (it must be, I logged a bug against it over a year ago and still no feedback!)
  • Axis 2 apparently has WSDL2.0 HTTP binding support with some restrictions (messages must be “IRI style” compatible). I’m not sure if one even needs to declare a HTTP binding in the WSDL, it seems to be automatically available for all services that have SOAP endpoints.
  • Apache Synapse looks nice, in a cute kind of way. I’m not sure I’d call it an ESB since it is really just a very thin routing framework that runs on top of Axis 2 - it doesn’t have any management interface per say and the overview might have been a bit forward looking with regard to the capabilities of the current implementation :-) Synapse looks more like an endpoint intermediary that you one might use to implement specific tasks (XPath/RegExp based routing, binding conversion, logging, endpoint authentication & authorization, transformation (XSLT, E4X, POJO based). I’m not sure you’d host your service implementations on it.
  • Apache Tuscany work is ongoing and I bet it will be for some time yet! I’m not certain of their claim that it will simplify the development of business solutions, if only because it is based on SCA which is turning into an absolute beast of a set of specifications - think “one spec to rule them all” type big, and with big specifications comes complexity, not simplification. From an implementation point of view, a huge problem is that the SCA specifications do not have either a reference implementation nor a compatibility test suite and according to Simon Nash and Jeremy Boynes (both of IBM) there are no current plans to develop either. Also it seems curious that the SCA specifications are not being developed under the auspices of an open body like OASIS, W3C or the OMG - why not? Some would say the overall approach seems incredibly vulnerable to repeat the mistakes of CORBA. It will also be interesting to see if any convincing response is given to Ron Ten-Hove’s recent critique of SCA.