Design proposal: synchronous authorization in Mesos

[Andrei Sekretenko <as...@d2iq.com>]

Hi all,
Probably you are aware that authorization in Mesos, as currently
implemented, always requires an asynchronous  step: after sending
authorization request to Authorizer (or requesting a short-lived
ObjectApprover from Authorizer), the caller has to wait (in one way or
another) for completion of a Future.

Recently, myself and a few of my colleagues started to explore an option to
implement synchronous authorization, which will allow to improve Operator
event API throughput, to simplify Master code and, most importantly, to get
rid of several bugs that are otherwise hard to fix cleanly.

The design proposal is here:
https://docs.google.com/document/d/12IVdCY668SGJTLhfEWciZfy2EreM_SJ-nzsTb33Tp44/edit?usp=sharing

Please take a look and comment!

Thanks,
Andrei Sekretenko