def spawn_scout(self):
assert not self.scout
self.ballot_num = Ballot(self.viewid, self.ballot_num.n,
self.ballot_num.leader)
sct = self.scout = self.scout_cls(self.member, self, self.ballot_num,
self.peers)
sct.start()
def test_accept_old_ballot(self):
proposal = Proposal('cli', 123, 'INC')
cmdid = CommanderId(address='CMD', slot=33, proposal=proposal)
self.ac.ballot_num = Ballot(10, 10)
self.node.fake_message('ACCEPT',
commander_id=cmdid,
ballot_num=Ballot(5, 5),
slot=33,
proposal=proposal)
self.assertMessage(
['CMD'],
'ACCEPTED',
commander_id=cmdid,
acceptor='F999',
# replies with newer ballot_num
ballot_num=Ballot(10, 10))
# and doesn't accept the proposal
self.assertState(Ballot(10, 10), {})
def test_accept_new_ballot(self):
proposal = Proposal('cli', 123, 'INC')
cmdid = CommanderId(address='CMD', slot=33, proposal=proposal)
self.ac.ballot_num = Ballot(10, 10)
self.node.fake_message('ACCEPT',
commander_id=cmdid,
ballot_num=Ballot(19, 19),
slot=33,
proposal=proposal)
self.assertMessage(
['CMD'],
'ACCEPTED',
commander_id=cmdid,
acceptor='F999',
# replies with updated ballot_num
ballot_num=Ballot(19, 19))
# and state records acceptance of proposal
self.assertState(Ballot(19, 19), {(Ballot(19, 19), 33): proposal})
def __init__(self, member, unique_id, commander_cls=Commander, scout_cls=Scout):
super(Leader, self).__init__(member)
self.ballot_num = Ballot(0, unique_id)
self.active = False
self.proposals = defaultlist()
self.commander_cls = commander_cls
self.commanders = {}
self.scout_cls = scout_cls
self.scout = None
self.peers = None
def preempted(self, ballot_num):
# ballot_num is None when we are preempted by a view change
if ballot_num:
self.logger.info("leader preempted by %s" % (ballot_num.leader,))
else:
self.logger.info("leader preempted by view change")
self.active = False
self.ballot_num = Ballot(
(ballot_num if ballot_num else self.ballot_num).n + 1, self.ballot_num.leader)
# if we're the primary for this view, re-scout immediately
if not self.scout and self.is_primary:
self.logger.info("re-scouting as the primary for this view")
self.spawn_scout()
def test_prepare_new_ballot(self):
proposal = Proposal('cli', 123, 'INC')
self.ac.accepted = {(Ballot(19, 19), 33): proposal}
self.ac.ballot_num = Ballot(10, 10)
self.node.fake_message(
'PREPARE',
scout_id=ScoutId(address='SC', ballot_num=Ballot(19, 19)),
# newer than the acceptor's ballot_num
ballot_num=Ballot(19, 19))
self.assertMessage(
['SC'],
'PROMISE',
scout_id=ScoutId(address='SC', ballot_num=Ballot(19, 19)),
acceptor='F999',
# replies with updated ballot_num
ballot_num=Ballot(19, 19),
# including accepted ballots
accepted={(Ballot(19, 19), 33): proposal})
self.assertState(Ballot(19, 19), {(Ballot(19, 19), 33): proposal})
def test_prepare_old_ballot(self):
self.ac.ballot_num = Ballot(10, 10)
self.node.fake_message(
'PREPARE',
scout_id=ScoutId(address='SC', ballot_num=Ballot(5, 10)),
# older than the acceptor's ballot_num
ballot_num=Ballot(5, 10))
self.assertMessage(
['SC'],
'PROMISE',
scout_id=ScoutId(address='SC', ballot_num=Ballot(5, 10)),
acceptor='F999',
# replies with newer ballot_num
ballot_num=Ballot(10, 10),
accepted={})
self.assertState(Ballot(10, 10), {})
def __init__(self, member):
super(Acceptor, self).__init__(member)
self.ballot_num = Ballot(-1, -1, -1)
self.accepted = defaultdict() # { (b,s) : p }