Description
While looking at some issues reported by jpplayer, we found that some of the default Hadoop proxyuser configuration properties in core-site.xml weren't working as intended.
devaraj's keen eye noticed that PQS was doing an unnecessary UGI ProxyUser impersonation check.
We can rely on the SPNEGO authentication as the barrier to use PQS, but then defer to the impersonation check that HBase is already doing as to which PQS instances are allowed to talk to HBase (defined by core-site.xml).