Re: [wildfly-dev] Subsystems to advertise implicit and optional dependencies to galleon

Hi, in the galleon project, in a context where we would not provision a complete server but just a subset required to run a given configuration, we have identified a need for subsystems to advertise to the galleon tooling some modules in addition to the modules galleon discover by traversing the module dependency tree. The first case is DeploymentProcessor injecting modules into the deployment units (implicit modules). The deployment injected ones are not required to be a dependency of the subsystem module, so galleon has the risk to miss some of them. As an example, in logging subsystem we have the following non optional injected modules : "org.jboss.logging", "org.apache.commons.logging", "org.apache.log4j", "org.slf4j", "org.jboss.logging.jul-to-slf4j-stub" Some of these modules are direct dependencies of logging subsystem, some others are indirect dependencies, others could be not present at all in the module dependency tree (eg: org.jboss.logging.jul-to-slf4j-stub). So we are thinking at solving this issue in 2 possible ways: 1) Mandate that all injected modules become dependencies of the subsystem module at the cost to load some useless modules at runtime. 2) Possibly better, make the subsystem to call RuntimeCapability.addAdditionalRequiredPackages (package name being module name) for each injected module. An existing capability or a new one would have to be created. There is also the case of optional injected module dependencies (eg: ee subsystem org.glassfish.javax.el, org.eclipse.yasson, ...). We need to treat them differently. When one is provisioning a server using galleon he can choose to exclude some packages from the provisioned server. Optional packages can be excluded without making the provisioned state invalid (as opposed to required package that can't be excluded). These optional implicit dependencies are typical usage of this, they are not required by the deployment unit to properly operate. For these, we plan to use RuntimeCapability.addAdditionalOptionalPackages. We can't make them "optional" in JBoss module. When galleon provision a subset of the server we don't include all optional dependencies. This brings the case of provisioning of optional dependencies present in JBOSS module.xml. We have identified multiple kind of optional dependencies. 1) The optional dependencies that are referencing modules only in use when a feature is present in the configuration of the subsystem (eg: jmx subsystem optional dep on org.jboss.remoting-jmx due to <remoting-connector/>, remoting subsystem optional dep on io.undertow.core for <http-connector/>, elytron subsystem optional dep on org.picketbox for <jacc-policy>) In order to have these dependencies to be provisioned with the subsystem, we can attach thanks to RuntimeCapability.addAdditionalRequiredPackages the modules to the feature. When the feature is present in the configuration, the module is no more optional but required. 2) The optional dependencies that reference modules that are part of another subsystems and only use if this other subsystem is present (eg: org.jboss.as.jpa optional dep on org.jboss.as.ejb3, org.jboss.as.transactions optional dep on org.jboss.remoting). These ones are simply not taken into account 3) The optional dependencies that reference modules that are not part of another subsystem (so are not provisioned by another source) but are only meaningful if the other subsystem is present. We call these ones "passive" (eg: org.jboss.as.weld optional dependency on org.jboss.as.weld.ejb|jpa|beanvalidation|webservices|transactions). "passive" are analyzed. If all their dependencies are present, then they are included. Some implicit optional dependencies can fall into this category (eg: org.jboss.jaxrs optional dep on org.jboss.resteasy.resteasy-validator-provider-11). The passive optional dependencies would be advertised with RuntimeCapability.addAdditionalPassiveOptionalPackages(optional dependency package name). So to summarize: - RuntimeCapability.addAdditionalRequiredPackages for all required implicit modules - RuntimeCapability.addAdditionalRequiredPackages to associate optional dependencies to a feature - RuntimeCapability.addAdditionalOptionalPackages for all optional implicit dependencies that are not passive - RuntimeCapability.addAdditionalPassiveOptionalPackages for all optional dependencies (implicit or not) that are passive

Is it something that subsystems owner would be ready to put in place to help galleon in this task? It would require a bit of analysis of the dependencies of your modules but the gain could be quite important.

early experimentation of this has shown a big reduction of the server filesystem footprint (web server + cdi has been reduced from 156MB to 46MB). The runtime memory usage reduction is not that big, but less modules being loaded we have a gain. Thanks for reading. JF _______________________________________________ wildfly-dev mailing list wildfly-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/wildfly-dev