def do_JOIN(self, requester):
# three is the minimum membership for a working cluster, so don't
# respond until then, but don't expand the peers list beyond 3
if len(self.peers) < 3:
self.peers.add(requester)
if len(self.peers) < 3:
return
# otherwise, we have a cluster, but don't welcome any nodes not
# part of that cluster (the cluster can do that itself)
if requester not in self.peers:
return
peer_history = dict((sl, self.peers) for sl in range(0, protocol.ALPHA))
self.send(
self.peers,
"WELCOME",
state=self.initial_state,
slot_num=protocol.ALPHA,
decisions=defaultlist(),
viewid=0,
peers=list(self.peers),
peer_history=peer_history.copy(),
)
# stick around for long enough that we don't hear any new JOINs from
# the newly formed cluster
if self.exit_timer:
self.cancel_timer(self.exit_timer)
self.exit_timer = self.set_timer(protocol.JOIN_RETRANSMIT * 2, self.stop)
def scout_finished(self, adopted, ballot_num, pvals):
self.scout = None
if adopted:
# pvals is a defaultlist of (slot, proposal) by ballot num; we need the
# highest ballot number for each slot. TODO: this is super
# inefficient!
last_by_slot = defaultlist()
for b, s in reversed(sorted(pvals.keys())):
p = pvals[b, s]
if last_by_slot[s] is None:
last_by_slot[s] = p
for s, p in enumerate(last_by_slot):
if p is not None:
self.proposals[s] = p
# re-spawn commanders for any potentially outstanding proposals
for view_slot in sorted(self.peer_history):
slot = view_slot + ALPHA
if self.proposals[slot] is not None:
self.spawn_commander(self.ballot_num, slot,
self.proposals[slot],
self.peer_history[view_slot])
# note that we don't re-spawn commanders here; if there are undecided
# proposals, the replicas will re-propose
self.logger.info("leader becoming active")
self.active = True
else:
self.preempted(ballot_num)
def do_JOIN(self, requester):
# three is the minimum membership for a working cluster, so don't
# respond until then, but don't expand the peers list beyond 3
if len(self.peers) < 3:
self.peers.add(requester)
if len(self.peers) < 3:
return
# otherwise, we have a cluster, but don't welcome any nodes not
# part of that cluster (the cluster can do that itself)
if requester not in self.peers:
return
self.send(self.peers,
'WELCOME',
state=self.initial_state,
slot_num=1,
decisions=defaultlist(),
viewid=0,
peers=list(self.peers))
# stick around for long enough that we don't hear any new JOINs from
# the newly formed cluster
if self.exit_timer:
self.cancel_timer(self.exit_timer)
self.exit_timer = self.set_timer(protocol.JOIN_RETRANSMIT * 2,
self.stop)
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 start(self, state, slot_num, decisions, viewid, peers):
self.state = state
self.slot_num = slot_num
# next slot num for a proposal (may lead slot_num)
self.next_slot = slot_num
self.decisions = defaultlist(decisions)
self.viewid = viewid
self.peers = peers
self.peers_down = set()
self.repropose()
def start(self, state, slot_num, decisions, viewid, peers, peer_history):
self.state = state
self.slot_num = slot_num
# next slot num for a proposal (may lead slot_num)
self.next_slot = slot_num
self.decisions = defaultlist(decisions)
self.viewid = viewid
self.peers = peers
self.peers_down = set()
self.peer_history = peer_history
self.welcome_peers = set()
assert decisions[slot_num] is None
self.catchup()
def scout_finished(self, adopted, ballot_num, pvals):
self.scout = None
if adopted:
# pvals is a defaultlist of (slot, proposal) by ballot num; we need the
# highest ballot number for each slot. TODO: this is super
# inefficient!
last_by_slot = defaultlist()
for b, s in reversed(sorted(pvals.keys())):
p = pvals[b, s]
if last_by_slot[s] is None:
last_by_slot[s] = p
for s, p in enumerate(last_by_slot):
if p is not None:
self.proposals[s] = p
for s, p in enumerate(self.proposals):
if p is not None:
self.spawn_commander(ballot_num, s, p)
self.logger.info("leader becoming active")
self.active = True
else:
self.preempted(ballot_num)
def __init__(self, member, execute_fn):
super(Replica, self).__init__(member)
self.execute_fn = execute_fn
self.proposals = defaultlist()
self.viewchange_proposal = None
