Hello Thomas, The Extension thing sounds ambitious! Several comments regarding class loading/unloading. As far as I know, there's no other way to lose a jar/class from the class loader then to lose the class-loader itself. In one of my projects, we had to provide ability to Upload/Re-upload different class implementations without the need to restart the server. We have developed a small plug-in manager based on java ability to load jars storing a hash-table [pluginName->classLoaderContext], if plug-in implementation needs to be updated, old record is thrown away and new one is placed instead. This might be potential cause of memory leaks, unless you do not reload classes too often and plug-in implementation is carefully checked (which is our case). I hope this helps. Would gladly hear any news in case if my knowledge in this area is somewhat outdated :) Regards, Roman -----Original Message----- From: devs-bounces(a)xwiki.org [mailto:devs-bounces@xwiki.org] On Behalf Of Thomas Mortagne Sent: Monday, September 13, 2010 8:51 PM To: XWiki Developers; XWiki Users Subject: [xwiki-devs] Extension Manager first working POC ! Hi xwikiers, Since May and actively since end of August I'm working on a POC for the future (long awaited) Extension Manager. It's now in a state where you can play with it a bit ! So here is a quick advertisement. You can find it on http://svn.xwiki.org/svnroot/xwiki/contrib/sandbox/xwiki-extension/ What it does already: - display remote extension and its dependencies as a tree - install remote extension and its dependencies from repositories - framework support any kind of extension using ExtensionInstaller component interface but only jar installer is implemented right now - framework support any kind of repository using RepositoryFactory component interface but only maven is implemented right now - load installed application when XWiki starts Critical features not yet supported: - miscellaneous rights protections in extension manager script service - uninstall/upgrade support: need to find a way to remove a jar from classloader. Note that you can remove an extension from local repository and restart. - xar installer: just need to provide a ExtensionInstaller implementation with role hint "xar" since this needs access to the whole model the first version will probably be implemented with old APIs (XWikiDocument, etc.) on xwiki-core side - install extension not coming from a repository: the current API is very repository centric but you can do it "by hand" by putting directly the extension jar file in the local repository. - real descriptors in local repository for installed extensions (to store in a repository independent way extension information as well as some local only metadas like the fact that an extension as been installed as a dependency of another etc.) - others on http://svn.xwiki.org/svnroot/xwiki/contrib/sandbox/xwiki-extension/README.t… I'm preparing some design documentation that will go on http://dev.xwiki.org/xwiki/bin/view/Design/ExtensionManagerProposal but i don't have much time right now so it will probably be tomorrow (GMT). The current state is not final at all but it still introduce a lot of APIs and design, lets call it an over designed POC. It needs to be discussed in all it's aspects before having its experimental tag removed. The plan is to distribute it with XE coming with 2.5 whatever it's state (when it does not represent a risk for XE obviously) as an experimental playground with all the required warnings in the UI and promote it when we are happy with a first version. Thanks, -- Thomas Mortagne _______________________________________________ devs mailing list devs(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/devs