ad hoc: description

three tiers
C++ app
OTP request broker same host as C++ app
remote OTP node

ad hoc protocol - went through two major versions
request: <Id><sync|async|handoff> <M,F,A>
reply:   <Id><reply data>

adds 1 thread for heartbeat

C++, heavy use of STL, fancy OO wrappers (functors) for callbacks