def get_replica_buckets(dest_host, dest_port_low, dest_port_high, timeout,
key):
viewleader_sock = common_functions.create_connection(
dest_host, dest_port_low, dest_port_high, timeout, True)
view, epoch = get_viewleader_info(viewleader_sock)
viewleader_sock.close()
replica_buckets = DHT.bucket_allocator(key, view)
return replica_buckets
def process_msg(self, recvd_msg, addr, sock):
function_from_cmd = recvd_msg[
"cmd"] # takes function arguments from received dict
if (function_from_cmd == 'query_servers'):
common_functions.send_msg(sock,
viewleader_rpc.query_servers(self.epoch),
False)
elif (function_from_cmd == 'heartbeat'):
new_id = recvd_msg["args"][0]
port = recvd_msg["args"][1] # src port
viewleader_rpc.heartbeat(new_id, port, addr, sock)
elif (function_from_cmd == 'lock_get'):
lock_name = recvd_msg["lock_name"]
requester_id = recvd_msg["requester_id"]
if (viewleader_rpc.lock_get(lock_name, requester_id) == True):
common_functions.send_msg(sock, "{'status': 'granted'}", False)
else:
common_functions.send_msg(sock, "{'status': 'retry'}", False)
print("Sending retry message to client.")
elif (function_from_cmd == 'lock_release'):
lock_name = recvd_msg["lock_name"]
requester_id = recvd_msg["requester_id"]
if (viewleader_rpc.lock_release(lock_name, requester_id) == True):
common_functions.send_msg(sock, "{'status': 'ok'}", False)
else:
common_functions.send_msg(sock, "{'status': 'not ok'}", False)
elif (function_from_cmd == 'get_buckets'):
key = recvd_msg["key"]
replica_buckets = DHT.bucket_allocator(key, viewleader_rpc.view)
common_functions.send_msg(sock, replica_buckets, False)
elif (function_from_cmd == 'update_view'):
curr_epoch = self.update_view()
common_functions.send_msg(sock, {'Current Epoch': curr_epoch},
False)
elif (function_from_cmd == 'rebalance'):
msg = recvd_msg['msg']
print(msg)
else:
print("Rejecting RPC request because function is unknown.")
def rebalance(self, new_view, old_view, epoch_op):
key_to_delete = ''
global key_value_replica
global data_in_view
for [[addr, port], server_id] in new_view:
try:
sock = common_functions.create_connection(
addr, port, port, 5, False)
except Exception as e:
print("Couldn't establish a connection with replica: ", e)
common_functions.send_msg(sock, {'cmd': 'get_data'}, False)
recvd_msg = common_functions.recv_msg(sock, False)
if (recvd_msg is not None):
for key, value in recvd_msg.items():
if (key not in data_in_view):
with self.lock:
data_in_view[key] = value
sock.close()
for key, value in data_in_view.items():
old_replicas = DHT.bucket_allocator(key, old_view)
new_replicas = DHT.bucket_allocator(key, new_view)
for [[addr, port], server_id] in new_replicas:
try:
sock = common_functions.create_connection(
addr, port, port, 5, False)
except Exception as e:
print("Couldn't establish a connection with replica: ", e)
common_functions.send_msg(sock, {
'cmd': 'get_data',
'key': key
}, False)
recvd_msg = common_functions.recv_msg(sock, False)
if (recvd_msg is not None) or (recvd_msg != ''):
key_value_replica = recvd_msg
sock.close()
with self.lock:
# print (key_value_replica)
try:
new_key, new_value = key_value_replica
if (new_key not in self.bucket):
try:
self.bucket[new_key] = new_value
print("Adding {}:{} to current replica...".format(
new_key, new_value))
except LookupError as e:
print(
"Couldn't set the key since there was no such key..."
)
else:
if (epoch_op == 'add'):
if (old_view is not None):
# print ("Old view: {}".format(old_view))
# print ("New view: {}".format(new_view))
# print ("unique_id: {}".format(self.unique_id))
for [[addr, port], server_id] in old_view:
# print ("tuple: {}".format([[addr, port], server_id]))
if (self.unique_id == server_id) and ([[
addr, port
], server_id] not in new_view):
print(
"Deleting {}:{} on old replica...".
format(new_key, new_value))
key_to_delete = new_key
try:
del self.bucket[key_to_delete]
except LookupError:
print(
"Couldn't delete the key since there was no such key..."
)
except Exception as e:
print("No key_value found: ", e)
def process_msg_from_client(self, recvd_msg):
function_from_cmd = recvd_msg[
"cmd"] # takes function arguments from received dict
try:
unique_id = recvd_msg["id"] # takes unique_id from received dict
except LookupError:
unique_id = None
# checks if function is print; if so, then take the text from the received dict
if (function_from_cmd == "print"):
text = recvd_msg["text"] # print's argument
# text length will always be > 0; if text length == 1,
# then make text into string rather than a list.
if (len(text) == 1):
text = text[0]
print("Printing " + str(text))
response = {'status': 'success', 'result': text, 'id': unique_id}
elif (function_from_cmd == "set"):
server_rpc.set(recvd_msg["key"], recvd_msg["val"])
response = {'status': 'success', 'id': unique_id}
elif (function_from_cmd == "get"):
result = server_rpc.get(recvd_msg["key"])
if (result is None):
response = {
'status': 'fail',
'result': result,
'id': unique_id
}
else:
response = {
'status': 'success',
'result': result,
'id': unique_id
}
elif (function_from_cmd == "query_all_keys"):
result = server_rpc.query_all_keys()
if (result is None):
response = {
'status': 'fail',
'result': result,
'id': unique_id
}
else:
response = {
'status': 'success',
'result': result,
'id': unique_id
}
elif (function_from_cmd == "get_id"):
# print ("Returning service_id to viewleader...".format(self.unique_id))
response = str(self.unique_id)
elif (function_from_cmd == "getr"):
with self.lock:
key = recvd_msg["key"]
try:
response = {
'status': 'success',
'result': self.bucket[key],
'id': unique_id
}
except LookupError:
response = {
'status': 'fail',
'result': '',
'id': unique_id
}
elif (function_from_cmd == "setr"):
with self.lock:
key = recvd_msg["key"]
value = recvd_msg["val"]
try:
self.bucket[key] = value
print("Stored {}:{} in this replica.".format(key, value))
response = {'status': 'success', 'id': unique_id}
except LookupError:
response = {'status': 'fail', 'id': unique_id}
elif (function_from_cmd == "request_vote"):
key = recvd_msg["key"]
if (key not in self.in_commit_phase):
self.in_commit_phase.append(key)
# print ("Added key to in_commit_phase: {}".format(self.in_commit_phase))
viewleader_epoch = recvd_msg["epoch"]
server_id = uuid.UUID(recvd_msg["server_id"]).hex
response = self.vote(viewleader_epoch, server_id)
else:
print("Aborting because there is a pending commit...")
response = 'abort'
print("Sending vote back to client...")
elif (function_from_cmd == "remove_commit"):
try:
key = recvd_msg["key"]
except LookupError:
print("No such key.")
# print ("Keys in in_commit_phase: {}".format(self.in_commit_phase))
# print ("Key: {}".format(key))
try:
self.in_commit_phase.remove(key)
except ValueError:
print("Key is not currently being committed.")
response = {'status': 'success', 'id': unique_id}
elif (function_from_cmd == "get_data"):
try:
key = recvd_msg["key"]
try:
response = (key, self.bucket[key])
except LookupError as e:
response = ''
except LookupError:
response = self.bucket
# print ("Couldn't find the key...")
elif (function_from_cmd == "rebalance"):
epoch_op = recvd_msg['op']
new_view = recvd_msg['new_view']
old_view = recvd_msg['old_view']
for key, value in self.bucket.items():
old_replicas = DHT.bucket_allocator(key, old_view)
new_replicas = DHT.bucket_allocator(key, new_view)
thread = threading.Thread(target=self.rebalance,
args=(new_view, old_view, epoch_op))
thread.start()
response = ''
else:
print("Rejecting RPC request because function is unknown.")
return response