[jboss-as7-dev] Subsystem specific deployer configurations in standalone.xml/domain.xml

I've been working $subject in order to help support Thomas Diesler's request for AS7-3694[1]. The gist of this request is to add deployment unit processing (DUP) configuration as children of the deployment resource itself. Thomas' OSGi use case is one place where this would be used. I expect HASingleton deployment will be another. WIP is at [2]. I'm looking for feedback. :) What I've done is based on what Thomas did at [3]. What I want to do is move from the generic key/value pairs in that patch to a more formally describable management API. Instead of: <deployment name="foo.war"...> <properties> <property name="start.policy" value="DEFERRED"/> <property> </deployment> It would be something analogous to how a profile configuration is done: <deployment name="foo.war"...> <deployment-subsystem xmlns="urn:jboss:domain:osgi:1.2"> <start-policy value="deferred"/> </deployment> </deployment> The existing Extension API already has the hooks to support this. Extensions can register xml parsers for children of the <deployment> element and can register management resources to act as children of the /deployment=foo.war resource as well. Several subsystems already take advantage of the latter. Until now the former has been an unimplemented API. The commit at [4] implements it. A couple things giving me some concern: 1) The above xml: <deployment-subsystem xmlns="urn:jboss:domain:osgi:1.2"> Nicer would be something like: <deployers> <subsystem xmlns="urn:jboss:domain:osgi:1.2"> I need to figure out if I can do some tricks with the parsing to allow that to happen. 2) The structure of the resource tree. We already support resources like this: /deployment=foo.war/subsystem=web Subsystems register resources like those to expose metrics. The commit at [4] uses that same tree. When subsystems could now register child resources to the deployment=* resource, they could include both runtime stuff and configuration stuff. I'm not sure that mixing the two is ideal, although it's what we do for the regular subsystem resources in the profile. I'm vaguely concerned that if someday the configuration that subsystems choose to expose via this mechanism gets complex, the mixing of metrics with configuration in the same tree will start to break down. Comments are appreciated. [1] https://issues.jboss.org/browse/AS7-3694 [2] https://github.com/bstansberry/jboss-as/commits/AS7-3694 [3] https://github.com/jbossas/jboss-as/pull/3230 [4] https://github.com/bstansberry/jboss-as/commit/6326003a104ac4ac825e8dda4c... -- Brian Stansberry Principal Software Engineer JBoss by Red Hat