HDP cluster takeover

[Anisha Agarwal <aa...@ddn.com>]

Hi All,

I am working on https://issues.apache.org/jira/browse/AMBARI-2852.

My current progress: I have been able to install Ambari on a working HDP cluster using the APIs, and skip the UI install wizard to go to monitoring dashboard directly. I see the correct component – host mapping.

After this, I need to indicate to the ambari-server that the services are started. But, the state transition rules prevent me from going to started from init.

>From what I see there are 2 ways to fix this:
1. When we create the services, we create them with the state "Installed"
2. Allow state transition from "Init" to "Started"

I think the first way is cleaner. What are your thoughts?

I have a couple of questions:

1.Can anyone please point me to the code where initialization of the services is done, and the state is set?
2. Where are the state transition rules defined? I found some defined here : controller/src/main/java/org/apache/ambari/resource/statemachine/ClusterImpl.java. Is there anything I am missing?

Also, any other pointers will be highly appreciated.

Thanks,
Anisha