Re: [wildfly-dev] Management Model: Squatter Resources

On Oct 30, 2014, at 9:12 AM, Jason Greene <jason.greene(a)redhat.com&gt; wrote: It sounds like in this case min/max is unnecessary because of the 1:1 address to name relationship. I think Jeff’s case is easily solved by returning fully qualified address based resource definitions. For example, if you do: /subsystem=messaging=*:read-resource-definition If the result contained nested N sets of resource definitions, as previously discussed, it’s all pretty straight forward. > On Oct 30, 2014, at 9:00 AM, Brian Stansberry <brian.stansberry(a)redhat.com&gt; wrote: > > I'm not so sure that bad idea was yours. > > But +1 on getting rid of the existing min/max thing. > > On 10/30/14, 8:58 AM, David M. Lloyd wrote: >> Using schema-ish things like min/max was probably a bad idea on my part. >> After trying to model XML schema in various ways for various reasons >> over the years, I know now that the simpler our rules are, the easier it >> will be to implement a cohesive and useful UX. >> >> IMO any currently unused and un-useful constructs like this that are >> hanging around probably need to be pruned, before someone actually uses >> them and makes everyone's live more difficult. :-) >> >> On 10/30/2014 08:44 AM, Brian Stansberry wrote: >>> No, we don't. That currently would have to be handled in a custom way by >>> the OSH that does the add for any of the children. >>> >>> There are some bits and pieces in the metadata that can help with doing >>> some sort of automated validation (i.e. a currently basically unused >>> max/min child count thing) but I don't think what's there is sufficient. >>> >>> The fact the metadata isn't there means a client like the console >>> couldn't enforce the constraint server side, for a better UX. >>> >>> On 10/30/14, 8:08 AM, David M. Lloyd wrote: >>>> I mean, a single child where there can be many possible types for that >>>> child. >>>> >>>> On 10/30/2014 08:01 AM, David M. Lloyd wrote: >>>>> I think that polymorphism is a new use case for 'squatters'. I wonder >>>>> if we have any existing code which enforces single children? >>>>> >>>>> On 10/30/2014 05:40 AM, Jeff Mesnil wrote: >>>>>> I’m integrating HornetQ 2.5 in WildFly and I have a new use case for resources that is related to singleton/squatter resources. >>>>>> >>>>>> In HornetQ 2.5 they have completely rewritten the HA configuration. Basically, a server can be configured as live-only, replicated (master, slave, or colocated) or using shared-store (again as a master, slave or colocated). >>>>>> >>>>>> To represent this in the management model, I have added several resources under hornetq-server: >>>>>> >>>>>> /subsystem=messaging/ >>>>>> hornetq-server=*/ >>>>>> ha-policy=live-only >>>>>> ha-policy=replicated-master >>>>>> ha-policy=replicated-slave >>>>>> ha-policy=replicated-colocated >>>>>> ha-policy=shared-store-master >>>>>> ha-policy=shared-store-slave >>>>>> ha-policy=shared-store-colocated >>>>>> >>>>>> I have constraints for this ha-policy resource: >>>>>> * There can at most one child for this type of resource (no child means no HA). This is enforces during the MODEL stage. >>>>>> * The child can only be named using one of the 7 values above (i.e. there is no resource definition for ha-policy=*, using any other name would fail) >>>>>> >>>>>> Each ha-policy definition has a different set of attributes. Using an attribute group to represent the HA policy does not seem a good fit as some of them have subresources too. >>>>>> >>>>>> I wonder if that representation fits with our roadmap and whether it can be considered as a singleton (as there can only be one resource of that type among). I have the additional constraints of having only one chile for that type that is not covered by your proposal though. >>>>>> >>>>>> I especially wonder how the console (and to a lesser extent the cli) can deal with this resource. >>>>>> >>>>>> Heiko, is it something that would make sense for the console based on this resource description: >>>>>> >>>>>> [standalone@localhost:9990 hornetq-server=default] ./ha-policy=*:read-resource-description(recursive-depth=1) >>>>>> { >>>>>> "outcome" => "success", >>>>>> "result" => [ >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "replication-colocated") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "replication-master") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "shared-store-slave") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "live-only") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "shared-store-master") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "replication-slave") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> }, >>>>>> { >>>>>> "address" => [ >>>>>> ("subsystem" => "messaging"), >>>>>> ("hornetq-server" => "default"), >>>>>> ("ha-policy" => "shared-store-colocated") >>>>>> ], >>>>>> "outcome" => "success", >>>>>> "result" => { >>>>>> ... >>>>>> } >>>>>> } >>>>>> ] >>>>>> } >>>>>> >>>>>> jeff >>>>>> >>>>> >>>> >>> >>> >> > > > -- > Brian Stansberry > Senior Principal Software Engineer > JBoss by Red Hat > _______________________________________________ > wildfly-dev mailing list > wildfly-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/wildfly-dev -- Jason T. Greene WildFly Lead / JBoss EAP Platform Architect JBoss, a division of Red Hat