> -----Original Message----- > From: Stephen McConnell [mailto:[EMAIL PROTECTED] > Sent: Monday, December 22, 2003 1:02 AM > > > > >>Also keep in mind that the Directory Project are working on a JNDI > >>InitialContextFactory that includes an embedded Merlin instance (part of > >>the Eve product) so this could also be leveraged (maybe - we would need > >>to check with Alex on this). > > > >This sounds exiting, yet I never heard about the Directory > Project, nor Eve. > >Any links? > > > > > > The Apache Directory project is an incubator project that is a result of > the > import of the SF ldapd project. At this time they don't have an > Apache site > in place but there is info on the old SF site at this address: > http://sf.net/projects/ldapd - aside from that there is the directory > project > mailing list - and naturally - Alex can provide lots of additional info.
Yes, I found the incubator entry, but the CVS repo on apache is empty. I'll check it out from sf then. Thanks, that'll probably help. > > To-date the documetation on Merlin has focussed on usage by the component > developer and assembler. The documetation concerning usage of internal > api is not in place - for example - how to embed merlin - manipulation > of the metamodel, etc., etc. > Manipulation of the metamodel? At runtime, programmatically? Is merlin aware of changes made to the metamodel after a deployment has been established, and will it adapt accordingly? This sounds exciting. > > > >So much to do, so little time ;) Just try to keep your head one > inch above > >the surface. Honestly, while not being an expert in this field, I do feel > >that JMX would be a viable road to follow. How about utilizing the > >commons-modeler package? > > > > > > It's been a long while since I looked a commons-modeler. WOuld it help at > tool level (e.g. JMX generation of descriptors etc. or am I totaly off > track)? > My attention was drawn to commons-modeler by it being mentioned as a core technology in tomcat 5. Following the article and a rather casual look into the docs I see two core concepts: (1) Model MBeans and their metadata are described in an xml config file, thus obviating the necessity to write those MBeans. (2) commons-modeler puts a facade called Registry before the MBean server. This registry will read in the xml descriptors, instantiate the corresponding MBeans, store the in the MBean server and subsequently manage them. So one could describe merlins building blocks as mbeans-descriptors, write a bootstrap class that takes those descriptors and builds a kernel from them which will be stored in the registry/mbean server. Does this make any sense? > > > > > >>(a) dynamic service aquisition is[n't] available yet (i.e. lookup of a > >>service without declaring a dependency) bu this is easy to do if you > >>emabedding merlin > >> > >> > > > >Could you elaborate on this? > > > > If you have access to a block then your basically emprowered to do a lot > of stuff. You can reach in a locate nested blocks, appliance instance, > resolve blocks and/or applicaes to services, manipulate the meta model, > decommission component, modify configurations, recomission, etc. > However - this is deep into the internals. Its basically what Merlin > uses to do its stuff. If fact - the "merlin" content is rather thin - > the real content is in the composition and activation packages. See above. Sounds great. Right now, I am struggling with understanding the source. At least in so far that I can get a birdeye view of what's going on in merlin. Its strength seems to be based in large parts on making implicit knowledge about the deployed app explicit. But after all, that's what metamodels are about. Thanks for your help, Olaf --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
