Support a hierarchical model of platform components at runtime (or typed relationships between such components)

It would be useful if PlatformComponents could have Set children at runtime, exposed through the API at runtime. For instance a notional ElasticWebCluster (platform component) could be built of an NginxComponent and multiple TomcatComponents (s/Tomcat/JBoss/Glassfish/etc) all of which are also platform components.

This would support a hierarchical view of what the application is consuming, so a user can see a high-level model (e.g. just the tiers) then drill-down as needed to see the clusters for each tier in each location, then even the individual processes making up that cluster.

This wouldn't be required, but to the extent the user wants to and the PaaS provider is willing to, this is quite a powerful and helpful capability, especially when debugging and working at scale.

Alternatively a "typed relationship" model could be used, similar to that used in graphs, where "IS_PARENT_OF" is one common relationship but other relationships could be defined. This might have other benefits such as noting inter-component requirements and dependencies.

This was raised by Alex Heneveld and was drupal issue # 1059