Subjects, already logged in, can't use them?

["Rose, Joseph" <Jo...@childrens.harvard.edu>]

Folks,

I’m trying to understand how Hadoop’s authentication architecture hangs
together. I already have a Subject with a Kerberos principal and
credentials, created programmatically using LoginContext. I’m using this
Subject to access other Kerberos-auth’ed services. Can I not use this
Subject (adding the right User principal so Hadoop will have its data) to
auth to Hadoop without having to log in again? What do I have to do to get
this Subject, or at least its principal, to work?

Thanks. I’m a little frustrated because it seems like it should be easier
than this.


-j