def send_prepare(_self, proposal_id):
'''
Broadcasts a Prepare message to all Acceptors
'''
status("Preparing", proposal_id)
msg = pxb.msg()
msg.type = pxb.PREPARE
msg.proposal_id = cPickle.dumps(proposal_id)
self._broadcast_message(msg)
def send_prepare(_self, proposal_id):
'''
Broadcasts a Prepare message to all Acceptors
'''
status("Preparing", proposal_id)
msg = pxb.msg()
msg.type = pxb.PREPARE
msg.proposal_id = cPickle.dumps(proposal_id)
self._broadcast_message(msg)
def send_heartbeat(_self, leader_proposal_id):
'''
Sends a heartbeat message to all nodes
'''
status("My heart still beats", leader_proposal_id)
msg = pxb.msg()
msg.type = pxb.HEARTBEAT
msg.proposal_id = cPickle.dumps(leader_proposal_id)
self._broadcast_message(msg)
def send_heartbeat(_self, leader_proposal_id):
'''
Sends a heartbeat message to all nodes
'''
status("My heart still beats", leader_proposal_id)
msg = pxb.msg()
msg.type = pxb.HEARTBEAT
msg.proposal_id = cPickle.dumps(leader_proposal_id)
self._broadcast_message(msg)
def send_prepare_nack(_self, to_uid, proposal_id, promised_id):
'''
Sends a Prepare Nack message for the proposal to the specified node
'''
status("Prepare Nack", proposal_id, promised_id)
msg = pxb.msg()
msg.type = pxb.NACK_PREPARE
msg.proposal_id = cPickle.dumps(proposal_id)
msg.previous_id = cPickle.dumps(promised_id)
self._send_message(to_uid, msg)
def send_accepted(_self, proposal_id, accepted_value):
'''
Broadcasts an Accepted message to all Learners
'''
status("Accepting", proposal_id, accepted_value)
msg = pxb.msg()
msg.type = pxb.ACCEPTED
msg.proposal_id = cPickle.dumps(proposal_id)
msg.value = cPickle.dumps(accepted_value)
self._broadcast_message(msg)
def send_accept(_self, proposal_id, proposal_value):
'''
Broadcasts an Accept! message to all Acceptors
'''
status("Accept!ing", proposal_id, proposal_value)
msg = pxb.msg()
msg.type = pxb.ACCEPT
msg.proposal_id = cPickle.dumps(proposal_id)
msg.value = cPickle.dumps(proposal_value)
self._broadcast_message(msg)
def send_prepare_nack(_self, to_uid, proposal_id, promised_id):
'''
Sends a Prepare Nack message for the proposal to the specified node
'''
status("Prepare Nack", proposal_id, promised_id)
msg = pxb.msg()
msg.type = pxb.NACK_PREPARE
msg.proposal_id = cPickle.dumps(proposal_id)
msg.previous_id = cPickle.dumps(promised_id)
self._send_message(to_uid, msg)
def send_accept_nack(_self, to_uid, proposal_id, promised_id):
'''
Sends a Accept! Nack message for the proposal to the specified node
'''
status("Accept Nack", proposal_id, promised_id)
msg = pxb.msg()
msg.type = pxb.NACK_ACCEPT
msg.proposal_id = cPickle.dumps(proposal_id)
msg.previous_id = cPickle.dumps(promised_id)
self._send_message(to_uid, msg)
def send_accepted(_self, proposal_id, accepted_value):
'''
Broadcasts an Accepted message to all Learners
'''
status("Accepting", proposal_id, accepted_value)
msg = pxb.msg()
msg.type = pxb.ACCEPTED
msg.proposal_id = cPickle.dumps(proposal_id)
msg.value = cPickle.dumps(accepted_value)
self._broadcast_message(msg)
def send_accept(_self, proposal_id, proposal_value):
'''
Broadcasts an Accept! message to all Acceptors
'''
status("Accept!ing", proposal_id, proposal_value)
msg = pxb.msg()
msg.type = pxb.ACCEPT
msg.proposal_id = cPickle.dumps(proposal_id)
msg.value = cPickle.dumps(proposal_value)
self._broadcast_message(msg)
def send_accept_nack(_self, to_uid, proposal_id, promised_id):
'''
Sends a Accept! Nack message for the proposal to the specified node
'''
status("Accept Nack", proposal_id, promised_id)
msg = pxb.msg()
msg.type = pxb.NACK_ACCEPT
msg.proposal_id = cPickle.dumps(proposal_id)
msg.previous_id = cPickle.dumps(promised_id)
self._send_message(to_uid, msg)
def do_paxos(self):
"""
Main Paxos loop
"""
for s,msg in self._get_messages():
if msg.proposal_id:
proposal_id = paxos.functional.ProposalID._make(cPickle.loads(str(msg.proposal_id)))
self.node.next_proposal_number = max(self.node.next_proposal_number, proposal_id.number + 1)
if msg.previous_id:
previous_id = paxos.functional.ProposalID._make(cPickle.loads(str(msg.previous_id)))
if msg.type == pxb.PREPARE:
self.node.recv_prepare(msg.from_uid, proposal_id)
elif msg.type == pxb.PROMISE:
previous_id = None
accepted_value = cPickle.loads(str(msg.value))
self.node.recv_promise(msg.from_uid, proposal_id, previous_id, accepted_value)
elif msg.type == pxb.ACCEPT:
self.node.recv_accept_request(msg.from_uid, proposal_id, cPickle.loads(str(msg.value)))
elif msg.type == pxb.ACCEPTED:
self.node.recv_accepted(msg.from_uid, proposal_id, cPickle.loads(str(msg.value)))
elif msg.type == pxb.NACK_PREPARE:
self.node.recv_prepare_nack(msg.from_uid, proposal_id, previous_id)
elif msg.type == pxb.NACK_ACCEPT:
self.node.recv_accept_nack(msg.from_uid, proposal_id, previous_id)
elif msg.type == pxb.HEARTBEAT:
self.node.recv_heartbeat(msg.from_uid, proposal_id)
elif msg.type == pxb.REQUEST:
if self.node.leader:
self.outbox.extend(cPickle.loads(str(msg.value)))
else:
status("Dropping request")
else:
raise NotImplementedError
if not self.incr_instance:
if self.outbox:
if self.node.leader and not self.node.proposed_value:
self.node.proposed_value = self.outbox
self.node.prepare()
elif not self.node.leader:
msg = pxb.msg()
msg.type = pxb.REQUEST
msg.value = cPickle.dumps(self.outbox)
self.outbox = []
self._broadcast_message(msg)
self.node.persisted()
if self.node.leader and self.node.next_hb <= time.time():
self.node.pulse()
else:
self.node = paxos.functional.HeartbeatNode(self.messenger, self.player, len(self.socks)/2 + 1, self.node.leader_uid)
self.node.next_hb = time.time()
self.instance += 1
self.incr_instance = False
def send_promise(_self, proposer_uid, proposal_id, previous_id, accepted_value):
'''
Sends a Promise message to the specified Proposer
'''
status("Promising", proposal_id, accepted_value)
msg = pxb.msg()
msg.type = pxb.PROMISE
msg.proposal_id = cPickle.dumps(proposal_id)
if previous_id:
msg.previous_id = cPickle.dumps(previous_id)
msg.value = cPickle.dumps(accepted_value)
self._send_message(proposer_uid, msg)
def send_promise(_self, proposer_uid, proposal_id, previous_id,
accepted_value):
'''
Sends a Promise message to the specified Proposer
'''
status("Promising", proposal_id, accepted_value)
msg = pxb.msg()
msg.type = pxb.PROMISE
msg.proposal_id = cPickle.dumps(proposal_id)
if previous_id:
msg.previous_id = cPickle.dumps(previous_id)
msg.value = cPickle.dumps(accepted_value)
self._send_message(proposer_uid, msg)
def _get_messages(self):
"""
Read from all of the sockets
"""
msgs = []
for s in self.socks:
if s:
try:
data = s.recv(1024)
while data:
msg = pxb.msg()
msg.ParseFromString(data)
if msg.instance > self.instance:
print "OLD"
msgs.append((s,msg))
data = s.recv(1024)
except IOError:
continue
return msgs
def _get_messages(self):
"""
Read from all of the sockets
"""
msgs = []
for s in self.socks:
if s:
try:
data = s.recv(1024)
while data:
msg = pxb.msg()
msg.ParseFromString(data)
if msg.instance > self.instance:
print "OLD"
msgs.append((s, msg))
data = s.recv(1024)
except IOError:
continue
return msgs
def do_paxos(self):
"""
Main Paxos loop
"""
for s, msg in self._get_messages():
if msg.proposal_id:
proposal_id = paxos.functional.ProposalID._make(
cPickle.loads(str(msg.proposal_id)))
self.node.next_proposal_number = max(
self.node.next_proposal_number, proposal_id.number + 1)
if msg.previous_id:
previous_id = paxos.functional.ProposalID._make(
cPickle.loads(str(msg.previous_id)))
if msg.type == pxb.PREPARE:
self.node.recv_prepare(msg.from_uid, proposal_id)
elif msg.type == pxb.PROMISE:
previous_id = None
accepted_value = cPickle.loads(str(msg.value))
self.node.recv_promise(msg.from_uid, proposal_id,
previous_id, accepted_value)
elif msg.type == pxb.ACCEPT:
self.node.recv_accept_request(
msg.from_uid, proposal_id,
cPickle.loads(str(msg.value)))
elif msg.type == pxb.ACCEPTED:
self.node.recv_accepted(msg.from_uid, proposal_id,
cPickle.loads(str(msg.value)))
elif msg.type == pxb.NACK_PREPARE:
self.node.recv_prepare_nack(msg.from_uid, proposal_id,
previous_id)
elif msg.type == pxb.NACK_ACCEPT:
self.node.recv_accept_nack(msg.from_uid, proposal_id,
previous_id)
elif msg.type == pxb.HEARTBEAT:
self.node.recv_heartbeat(msg.from_uid, proposal_id)
elif msg.type == pxb.REQUEST:
if self.node.leader:
self.outbox.extend(cPickle.loads(str(msg.value)))
else:
status("Dropping request")
else:
raise NotImplementedError
if not self.incr_instance:
if self.outbox:
if self.node.leader and not self.node.proposed_value:
self.node.proposed_value = self.outbox
self.node.prepare()
elif not self.node.leader:
msg = pxb.msg()
msg.type = pxb.REQUEST
msg.value = cPickle.dumps(self.outbox)
self.outbox = []
self._broadcast_message(msg)
self.node.persisted()
if self.node.leader and self.node.next_hb <= time.time():
self.node.pulse()
else:
self.node = paxos.functional.HeartbeatNode(
self.messenger, self.player,
len(self.socks) / 2 + 1, self.node.leader_uid)
self.node.next_hb = time.time()
self.instance += 1
self.incr_instance = False