def get_consistency_helper(self, key, socket, contact):
msg = store.Msg()
msg.pair_read.key = key
msg.pair_read.val = self.keyValStore[key].split(":")[0]
socket.sendall(msg.SerializeToString())
response = socket.recv(1024)
msg = store.Msg()
if response:
msg.ParseFromString(response)
if msg.WhichOneof("msg") == "suc":
if msg.suc.success == True:
self.OKs.append(True)
else:
if self.const_mech == 0:
# do a read repair
self.RR_lock.acquire()
if self.handling_read_repair == False:
self.handling_read_repair = True
self.RR_lock.release()
self.read_repair(key)
else:
self.RR_lock.release()
thread.exit()
def waitForInstruction(self):
print("Waiting for coordinator <" + str(self.coordinator) +
"> to assign a request")
if (self.recoveryFlag):
t = threading.Thread(target=self.attemptToConnect)
t.start()
t.join()
#Hinted Handoff Consistency Mechanism
if (self.const_mech == 1):
self.performHintedHandoff()
try:
coordinatorSocket = self.neighborSockets[self.coordinator]
time.sleep(2)
msg = coordinatorSocket.recv(1024)
store_msg = store.Msg()
store_msg.ParseFromString(msg)
msgType = store_msg.WhichOneof("msg")
valid = self.parse_msg(coordinatorSocket, ("", ""), store_msg)
if (valid == "False"):
return
elif (valid == "True"):
msg = store.Msg()
msg.suc.success = True
coordinatorSocket.sendall(msg.SerializeToString())
except (KeyboardInterrupt, OSError) as e:
if self.clientSocket:
self.clientSocket.close()
self.clientSocket = None
for sock in self.neighborSockets:
if sock:
sock.close()
sock = None
sys.exit()
def get(self, key, level, client_socket):
consistency_worked = None
if key in self.keyValStore:
val_to_send = self.keyValStore[key].split(":")
val_to_send = val_to_send[0]
time_stamp = val_to_send[1]
consistency_worked = self.get_consistency(key, level)
msg_to_send = store.Msg()
msg_to_send.string_val.val = val_to_send
client_socket.sendall(msg_to_send.SerializeToString())
else:
#we contact the next replica in the ring
msg_to_send = store.Msg()
msg_to_send.suc.success = False
client_socket.sendall(msg_to_send.SerializeToString())
for i in range(4):
if i == int(self.replica_num):
continue
sock = self.neighborSockets[i]
self.reset_msg(sock, 0)
consistency_worked = True
'''
sock_to_contact = self.neighborSockets[(int(self.replica_num) + 1) % 4]
msg_to_send = store.Msg()
msg_to_send.get.key = key
msg_to_send.get.level = level
print("key is not in this node, asking next node...")
sock_to_contact.sendall(msg_to_send.SerializeToString())
val = sock_to_contact.recv(1024)
if val:
msg_to_respond = store.Msg()
msg_to_respond.ParseFromString(val)
if msg_to_respond.WhichOneof("msg") == "string_val":
msg = store.Msg()
msg.string_val.val = msg_to_respond.string_val.val
client_socket.sendall(msg.SerializeToString())
consistency_worked = True
'''
if consistency_worked == True:
return
else:
# send a message to the client that it didn't work
not_OK = store.Msg()
not_OK.suc.success = False
client_socket.sendall(not_OK.SerializeToString())
def retrieve_timestamp(self, key, socket):
msg = store.Msg()
msg.pair_read.key = key
msg.pair_read.val = self.keyValStore[int(key)]
socket.sendall(msg.SerializeToString())
write_this = socket.recv(1024)
#call pair_write
if write_this:
s = store.Msg()
s.ParseFromString(write_this)
if s.WhichOneof("msg") == "pair_write":
self.pair_write(s.pair_write.key, s.pair_write.val)
def performHintedHandoff(self):
msg = store.Msg()
time.sleep(int(self.replica_num))
if (len(self.hints[self.coordinator]) > 0):
print("I have hints for the coordinator")
k = []
v = []
for i in range(len(self.hints[self.coordinator])):
k.append(self.hints[self.coordinator][i][0])
v.append(self.hints[self.coordinator][i][1])
msg.hint.hintKey.extend(k)
msg.hint.hintValue.extend(v)
print(self.hints[self.coordinator])
self.hints[self.coordinator].clear()
print(self.hints)
else:
print("No hints for the coordinator")
noHint = []
noHint.append(-1)
noVal = []
noVal.append("-")
msg.hint.hintKey.extend(noHint)
msg.hint.hintValue.extend(noVal)
self.neighborSockets[self.coordinator].sendall(msg.SerializeToString())
def read_repair(self, key):
begins = self.bytePartitioner(key)
timestamps = {} # replica num => timestamp
msg = store.Msg()
msg.timestamp.key = key
for i in range(3):
contact = (int(begins) + i) % 4
if int(contact) == int(self.replica_num):
continue
socket = self.neighborSockets[contact]
# we want to find out who has the latest version of the object
socket.sendall(msg.SerializeToString())
response = socket.recv(1024)
parser = store.Msg()
if response:
parser.ParseFromString(response)
if parser.WhichOneof("msg") == "pair_read":
timestamps[contact] = parser.pair_read.val
#now that we have all the timestamps of all the replicas we have to compare the
# timestamps
timestamps[int(
self.replica_num)] = self.keyValStore[key] # add our own verison
max_timestamp = 0
max_val = ""
for replica_num, val in timestamps.items():
value, timestamp = val.split(":")
timestamp = float(timestamp)
if max_timestamp < timestamp:
max_timestamp = timestamp
max_val = value
self.keyValStore[key] = max_val + ":" + str(time.time())
read_repair_msg = store.Msg()
read_repair_msg.pair_write.key = key
read_repair_msg.pair_write.val = max_val
for i in range(3):
contact = (int(begins) + i) % 4
if int(contact) == int(self.replica_num):
continue
socket = self.neighborSockets[contact]
socket.sendall(read_repair_msg.SerializeToString())
def send_put_msg(self, key, val, consistency):
msg = store_pb2.Msg()
msg.put.key = key
msg.put.val = val
msg.put.level = consistency
self.coordinatorSocket.sendall(msg.SerializeToString())
val = self.coordinatorSocket.recv(1024)
if val:
s = store_pb2.Msg()
s.ParseFromString(val)
if (s.suc.success):
print("Write operation completed successfully")
else:
print("Failed to write to replicas desired")
def send_get_req(self, key, consistency):
msg = store_pb2.Msg()
msg.get.key = key
msg.get.level = consistency
self.coordinatorSocket.sendall(msg.SerializeToString())
val = self.coordinatorSocket.recv(1024)
if val:
s = store_pb2.Msg()
s.ParseFromString(val)
if s.WhichOneof("msg") == "string_val":
value = s.string_val.val
index = value.find("M") + 1
print("Key: " + str(key) + " => " + value[index:])
elif s.WhichOneof("msg") == "suc":
self.sendInitialization(int(self.cur_coordinator) + 1)
corIP = self.replicaList[self.cur_coordinator][0]
cor_port = self.replicaList[self.cur_coordinator][1]
self.coordinatorSocket = socket.socket(socket.AF_INET,
socket.SOCK_STREAM)
self.coordinatorSocket.connect((corIP, cor_port))
self.send_get_req(key, consistency)
def compare_pair(self, key, val, sock):
msg = store.Msg()
print(self.keyValStore)
if key in self.keyValStore:
if self.keyValStore[key].split(":")[0] == val:
msg.suc.success = True
else:
msg.suc.success = False
else:
msg.suc.success = False
sock.sendall(msg.SerializeToString())
timestamp = sock.recv(1024)
parser = store.Msg()
parser.ParseFromString(timestamp)
if parser.WhichOneof("msg") == "timestamp":
self.retrieve_timestamp(key, sock)
def coordinatorFunction(self, client_sock, client_add, store_msg):
if self.recoveryMode:
for replica in reversed(self.replicaList):
index = self.replicaList.index(replica)
if (index == int(self.replica_num)):
continue
else:
incomingConn, incomingAddr = self.clientSocket.accept()
'''
for every replica in replicaList
ip = replica[0].getIp()
if incomingAddr[0] == ip
self.neighborSockets[replicaList.index(replica)] = incomingConn
'''
self.neighborSockets[self.replicaList.index(
replica)] = incomingConn
print("Got connection from " + str(index) + ": {" +
incomingAddr[0] + ", " + str(incomingAddr[1]) + "}")
print("")
#Wait to receive hints if consistency mechanism is hinted handoff
if (self.const_mech == 1):
self.receiveHintedHandoff(client_sock)
infoMsg = client_sock.recv(1024)
if infoMsg:
store_msg = store.Msg()
store_msg.ParseFromString(infoMsg)
self.parse_msg(client_sock, client_add, store_msg)
def sendInitialization(self, coordinator):
self.cur_coordinator = int(coordinator)
for replica in replicaList:
initSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
initSocket.connect((replica))
except:
print("Can't connect")
continue
msg = store_pb2.Msg()
msg.init.coordinator = coordinator
initSocket.sendall(msg.SerializeToString())
initSocket.close()
def receiveHintedHandoff(self, socket):
print("")
print("---------------Handling Hints---------------")
print("")
time.sleep(2)
hintMessagesReceived = 0
for socket in self.neighborSockets:
if (self.neighborSockets.index(socket) == self.coordinator):
continue
else:
msg = socket.recv(1024)
if msg:
store_msg = store.Msg()
store_msg.ParseFromString(msg)
msgType = store_msg.WhichOneof("msg")
ret = self.parse_msg(socket, ("", ""), store_msg)
if (ret == "True"):
print("Got a hint from " +
str(self.neighborSockets.index(socket)))
elif (ret == "False"):
print("No hint from " +
str(self.neighborSockets.index(socket)))
print(self.keyValStore)
print("")
print("-------------Done Handling Hints-------------")
print("")
def run(self):
self.clientSocket.bind(('', self.portNum))
print("Starting Replica " + self.replica_num + ": {" + self.hostName +
":" + str(self.portNum) + "}")
self.neighborSockets[int(self.replica_num)] = self.clientSocket
self.clientSocket.listen(30)
print("---------------Connecting All Replicas---------------")
print("")
if not self.recoveryMode:
self.initializeNeighboringSockets()
print("--------------Ready To Receive Requests--------------")
#Check for write-log file
writeLog = Path("./" + self.logName)
if (writeLog.exists()):
self.parseWriteLog()
while True:
client_sock = None
client_add = None
try:
while (self.coordinator == -1):
try:
client_sock, client_add = self.clientSocket.accept()
msg = client_sock.recv(1024)
if msg:
store_msg = store.Msg()
store_msg.ParseFromString(msg)
msgType = store_msg.WhichOneof("msg")
self.parse_msg(client_sock, client_add, store_msg)
except KeyboardInterrupt or AttributeError:
if self.clientSocket:
self.clientSocket.close()
for sock in self.neighborSockets:
if sock:
sock.close()
break
#Replica
if (self.replica_num != str(self.coordinator)):
self.waitForInstruction()
#coordinator
else:
print("Connected to client as coordinator: {" +
client_add[0] + ":" + str(client_add[1]) + "}")
self.coordinatorFunction(client_sock, client_add,
store_msg)
except KeyboardInterrupt:
for sock in self.neighborSockets:
if sock:
sock.close()
if self.clientSocket:
self.clientSocket.close()
break
self.coordinator = -1
client_sock.close()
def put(self, key, val, level, client_socket):
#Determine how many replicas are needed before returning to client
replicasForConsistency = level + 1
#First replica determined by the byte partitioner
firstReplica = self.bytePartitioner(key)
#Second and third are clockwise in the cluster
secondReplica = (firstReplica + 1) % 4
thirdReplica = (firstReplica + 2) % 4
operationReplicas = [firstReplica, secondReplica, thirdReplica]
print("I will be storing this data on")
print(
str(firstReplica) + " " + str(secondReplica) + " " +
str(thirdReplica))
#Amount of replicas that have successfully completed the request
successfulPuts = 0
#Loop through all four replcias
for i in range(4):
#Send to only those replicas desired by coordinator
if (i in operationReplicas):
#Create message to send to replicas
msg = store.Msg()
msg.pair_write.key = key
msg.pair_write.val = val
index = operationReplicas.index(i)
#This replica is required to store the info
if (operationReplicas[index] == int(self.replica_num)):
#Write to log before adding to local memory
self.storeLock.acquire()
writeLogInfo = open(self.logName, "a")
writeLogInfo.write(
str(key) + ":" + val + ":" + str(time.time()) + "\n")
writeLogInfo.close()
self.keyValStore[key] = val
self.storeLock.release()
#"Put" was successful, return to client if consistency level is met
if key in self.keyValStore:
print("Added: " + val + " to location: " + str(key))
successfulPuts += 1
#We have reached QUORUM or ONE consistency
if (successfulPuts == replicasForConsistency):
msg_to_send = store.Msg()
msg_to_send.suc.success = True
client_socket.sendall(
msg_to_send.SerializeToString())
continue
#Find socket connecting to other replica
repSock = self.neighborSockets[operationReplicas[index]]
time.sleep(0.5)
#Send message containing key and val to replica
try:
repSock.sendall(msg.SerializeToString())
except socket.error:
self.neighborSockets[i].close()
print("Failed to connect to " + str(i))
if (self.const_mech == 1):
print("Storing <" + str(key) + val + "> as a hint")
self.hints[i].append((key, val))
print(self.hints)
continue
#Sleep to see effect of consistency level
time.sleep(2)
#Receive response
try:
msg = repSock.recv(1024)
except socket.error:
self.neighborSockets[i].close()
print("Failed to connect to " + str(i))
if (self.const_mech == 1):
print("Storing <" + str(key) + val + "> as a hint")
self.hints[i].append((key, val))
print(self.hints)
continue
store_msg = store.Msg()
store_msg.ParseFromString(msg)
msgType = store_msg.WhichOneof("msg")
valid = self.parse_msg(repSock, ("", ""), store_msg)
#The put in a replica was successful
if (valid):
print("Successful copy to " +
str(operationReplicas[index]))
successfulPuts += 1
#We have enough for the consistency, send success to client
if (successfulPuts == replicasForConsistency):
msg_to_send = store.Msg()
msg_to_send.suc.success = True
client_socket.sendall(msg_to_send.SerializeToString())
continue
else:
print("Failed copy to " + str(operationReplicas[index]))
#Append hint to list for replica that failed
self.neighborSockets[i].close()
print("Failed to connect to " + str(i))
if (self.const_mech == 1):
print("Storing <" + str(key) + val + "> as a hint")
self.hints[i].append((key, val))
print(self.hints)
continue
#Message to get unused replcias out of the wait function
else:
if (i == int(self.replica_num)):
continue
msg = store.Msg()
msg.pair_write.key = -1
msg.pair_write.val = "None"
repSock = self.neighborSockets[i]
time.sleep(0.5)
repSock.sendall(msg.SerializeToString())
#Send failure to client
if (successfulPuts < replicasForConsistency):
print("Didn't get to consistency level")
msg_to_send = store.Msg()
msg_to_send.suc.success = False
client_socket.sendall(msg_to_send.SerializeToString())
def reset_msg(self, socket, contact):
msg = store.Msg()
msg.pair_write.key = -1
msg.pair_write.val = ":)"
socket.sendall(msg.SerializeToString())
thread.exit()
