ResourceManager REST endpoint doesn't expose ApplicationManager RPC endpoint

[Richard Lee <rd...@tivo.com>]

Hi there-

It appears from my initial searching that the ResourceManager REST endpoint only exposes a proxy url for the ApplicationManager trackingUI, but gives no indication of what the ApplicationManager RPC port might be for making REST requests to the ApplicationManager.  Now, some ApplicationManagers (like MapReduce) kindly put their REST endpoints under their tracking UI endpoints (via /ws/v1/mapreduce).  However, other ApplicationManagers (like Samza) do not, and place them on a different random port entirely.

It would be nice if the ResourceManager REST endpoint reported the RPC port of the ApplicationManager.  I’m told that I can look this up using YarnClient.getApplicationReport(), but that then would require pulling in the whole YARN image just to look up a REST endpoint, which sort of defeats the purpose of having a lightweight REST endpoint in the first place.

Richard