def releaseServer(self, serveraddress):
''' REST Endpoint for a client to release the server.
Decrements the load count on server
'''
if (serveraddress not in self.servers):
return json.dumps({
"response":
"failure",
"message":
"No server with address %s found" % (serveraddress)
})
if (self.servers[serveraddress] == 0):
return json.dumps({
"response": "failure",
"message": "No load on %s" % (serveraddress)
})
self.mutex.acquire()
try:
self.servers[serveraddress] -= 1
r = requests.get("http://" + serveraddress + "/unregisterClient")
utils.check_response_for_failure(r.text)
finally:
self.mutex.release()
return json.dumps({"response": "success"})
def passElection(self, *args):
'''
An API for the first pass in the ring. Every server pushes it's load.
:param args:
:return:
'''
if not self.servers:
self.get_info()
sz = len(args)
ids = [args[x] for x in range(sz / 2)]
loads = [int(args[x]) for x in range(sz / 2, sz)]
if self.id in ids: # Time to find and elect leader
minm = min(loads)
indices = [i for i, x in enumerate(loads) if x == minm]
subset_ids = [ids[i] for i in indices]
leader_addr = min(subset_ids)
r = requests.get('http://' + self.disp_addr + '/releaseLeaderElectionLock')
utils.check_response_for_failure(r.text)
self.coordinatorMessage(leader_addr)
else: # Pass on the message
ids.append(self.id)
loads.append(str(self.get_load()))
arg = '/'.join(ids) + '/' + '/'.join([str(load) for load in loads])
r = requests.get('http://' + self.next_server + '/passElection/%s' % (arg))
obj = utils.check_response_for_failure(r.text)
return json.dumps({"response": "success"})
def getServer(self):
''' REST endpoint for getting server.
Returns the address to server and increments the load count
'''
self.mutex.acquire()
# Cannot use reader writer locks because following code requires
# both reader and writer lock are required. Hence, using threading.RLock.
try:
minload = sys.maxint
minload_server = None
for server in self.servers:
if minload > self.servers[server]:
minload = self.servers[server]
minload_server = server
assert (minload != sys.maxint and minload_server != None)
self.servers[minload_server] += 1
finally:
self.mutex.release()
if (minload_server == None):
return json.dumps({
"response": "failure",
"message": "Failed to get server, try again"
})
r = requests.get("http://" + minload_server + "/registerClient")
utils.check_response_for_failure(r.text)
return json.dumps({"response": "success", "server": minload_server})
def releaseServer(self):
'''
Release Server.
'''
if (self.server_address == ""):
print "Server not registered"
return
r = requests.get(self.dispatcher_address + '/releaseServer/' + self.server_address)
utils.check_response_for_failure(r.text)
self.server_address = ""
def set_slave_times(self, average_time):
'''
Set the time of the slaves.
:param average_time:
:return:
'''
for addr in self.server_addresses:
r = requests.get("http://" + addr + "/setClock/" +
str(average_time))
utils.check_response_for_failure(r.text)
print "All slaves changed with offset", average_time
def newElection(self):
'''
Start a new leader.
:return:
'''
print "newelection next_server", self.next_server
r = requests.get('http://' + self.next_server + '/passElection/%s/%d' % (self.id, self.get_load()))
obj = utils.check_response_for_failure(r.text)
def get_clock_from_address(self, address):
''' Get signed clock offset from given address
'''
assert (self.is_leader())
r = requests.get("http://" + address + "/getClock/%d" %
(self.get_current_time_offset()))
obj = utils.check_response_for_failure(r.text)
return int(obj.clock)
def __raffle_thread_func(self):
while self.__raffle_running:
time.sleep(config.RAFFLE_TIME)
r = requests.get('http://' + self.servers.keys()[0] +
'/chooseRaffleWinner/%f' % (random()))
obj = utils.check_response_for_failure(r.text)
print "Winner of Raffle is", obj.winner
for server in self.servers.keys():
r = requests.get('http://' + server + "/clearReqQueue")
def getServer(self):
'''
The front-end server,which cacofonix should call.
'''
if (self.server_address != ""):
return
print "Getting server"
r = requests.get(self.dispatcher_address + '/getServer')
obj = utils.check_response_for_failure(r.text)
self.server_address = obj.server
print "Server Address obtained", self.server_address
def getServer(self):
'''
Query the dispatcher about the front-end server that this client needs to connect with.
:return:
'''
if (self.server_address != ""):
return
print "Getting server"
r = requests.get(self.dispatcher_address + '/getServer')
obj = utils.check_response_for_failure(r.text)
self.server_address = "http://" + obj.server
print "Server Address obtained", self.server_address
def incrementMedalTally(self, team, medalType, authID=config.AUTH_ID, to_print=True):
self.getServer()
if team not in utils.teams:
raise Exception("Invalid Team Name '%s'" % team)
if medalType not in utils.medals:
raise Exception("Invalid medal type '%s'" % medalType)
r = requests.get("http://" + self.server_address + '/incrementMedalTally/%s/%s/%s' % (team, medalType, authID))
obj = utils.check_response_for_failure(r.text)
if (to_print):
print "Operation Successful"
return obj
def parse_getmedaltally_response(self, response, to_print):
"""
Parses server's response to the GET API and prints only in debug mode.
"""
obj = utils.check_response_for_failure(response)
if to_print:
print "Medals and Timestamps:"
for medal in utils.medals:
print medal, "= ", getattr(
obj.medals, medal), "last updated at", time.ctime(
float(getattr(obj.time, medal)))
return obj
def perpetual_election(self):
'''
Runs on a thread perpetually. Purpose: Start Election.
:return:
'''
while self.__do_leader_election: # TODO
time.sleep(config.ELECTION_SNOOZE)
if self.__do_leader_election:
if not self.servers:
self.get_info()
r = requests.get('http://' + self.disp_addr + '/getLeaderElectionLock')
obj = utils.check_response_for_failure(r.text)
if obj.can_lock:
print "start new election ", self.id
self.newElection()
def parse_getscore_response(self, response, to_print):
"""
Parses server's response to the GET API and prints only in debug mode.
"""
obj = utils.check_response_for_failure(response)
if to_print:
print "Score:"
for team in utils.teams:
if hasattr(obj.scores, team):
print team, ":", getattr(
obj.scores, team), "last updated at", time.ctime(
float((getattr(obj.time, team))))
return obj
def setScore(self, eventType, romeScore, gaulScore, authID=config.AUTH_ID, to_print=True):
self.getServer()
if not romeScore.isdigit():
raise Exception("Rome Score '%s' is not a positive integer" % (romeScore))
if not gaulScore.isdigit():
raise Exception("Gaul Score '%s' is not a positive integer" % (gaulScore))
if eventType not in utils.games:
raise Exception("Invalid team name '%s'" % eventType)
r = requests.get(
"http://" + self.server_address + '/setScore/%s/%s/%s/%s' % (eventType, romeScore, gaulScore, authID))
obj = utils.check_response_for_failure(r.text)
if to_print:
print "Operation Successful"
return obj
def get_all_front_end_servers(self):
r = requests.get(
'http://' + self.disp_addr + '/getAllFrontEndServers/')
print r.text
obj = utils.check_response_for_failure(r.text)
return obj.servers
def get_all_servers(self):
print "get all servers " + self.disp_addr
r = requests.get('http://' + self.disp_addr + '/getAllServers/')
obj = utils.check_response_for_failure(r.text)
return obj.servers
