09/04: Two Professor’s Problem

The two professor’s problem is basically a two general’s problem except that the generals are replaced with professors and the soldiers are now birds.

Proposed algorithm (in sudo code):


chosse dates
order list in ascending order
send list to the other professor


receive list
wait until timeout
if (rcv)
choose the earliest acceptable date
resend msg
goto wait


Other possible enhacement to be made:

  • Assume bound communication
  • Adaptive timeout
  • Fault masking:
    • message retransmission
    • send heartbeat messages (telling the other professor that I have not yet crushed but still working on the schedule)
  • Reliability:
    • Use more birds to flood the message
    • Quorum: Increase the number of professors
      So we only need the majority votes and ignored the crushed professor
  • Fault detector:
    • Use admin to check if the prof is still there