def request_vote_from_peers(self):
if self.state != ConsensusState.CANDIDATE:
return
votes_received = 1
peers = {server: address for server, address in cluster_info_by_name.items() if self.raft_server.name != server}
# We can use a with statement to ensure threads are cleaned up promptly
with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
future_to_server = {executor.submit(self.do_rpc_request, server, address): server for
server, address in peers.items()}
for future in concurrent.futures.as_completed(future_to_server):
server = future_to_server[future]
try:
data = future.result()
except Exception as exc:
print(f"{self.raft_server.name} : [ {server} ] generated an exception {exc}")
else:
print(f"{self.raft_server.name} : Result from {server} of the Request Vote response {data}")
if self.state != ConsensusState.CANDIDATE:
print(
f"{self.raft_server.name} : while waiting for the reply state changed {state_to_name[self.state]}")
return
if data.VoteGranted:
votes_received = votes_received + 1
print(f"{self.raft_server.name} : For a current term {self.current_term} the votes received {votes_received}")
nodes_that_can_fail = (len(cluster_info_by_name) - 1) / 2
if votes_received > nodes_that_can_fail:
print(f"{self.raft_server.name} : Got majority of votes .. Lets roll and become leader")
self.become_leader()
# Run timer in case of split votes
self.run_election_timer()
def send_heart_beat(self):
peers = {server: address for server, address in cluster_info_by_name.items() if self.raft_server.name != server}
# We can use a with statement to ensure threads are cleaned up promptly
with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
future_to_server = {executor.submit(self.do_heartbeat_rpc_request, server, address): server for
server, address in peers.items()}
for future in concurrent.futures.as_completed(future_to_server):
server = future_to_server[future]
try:
data = future.result()
except Exception as exc:
print(f"{self.raft_server.name} : [ {server} ] generated an exception {exc}")
else:
print(f"{self.raft_server.name} : Result from {server} of the Heart Beat response {data}")
if data.Term > self.current_term:
print(f"{self.raft_server.name} : Term out of date in Heartbeat reply")
self.become_follower(data.Term)
return
def connect_rpc_clients(self):
while True:
for server, address in cluster_info_by_name.items():
if server != self.name:
if self.consensusModule.peers.get(server, None) is None:
print(
f"{self.name} : trying to connect to {server} at {address}"
)
try:
remote = RPCProxy(cluster_info_by_name[server],
authkey=b"peekaboo",
timeout=2)
except Exception as e:
print(
f"{self.name} : [ {server} ] generated an exception: {e}"
)
else:
self.consensusModule.peers[server] = remote
time.sleep(1)