def handleConnection(messageQueue, server_address,port,resultsDirectory):
'''Handles Connection to Server. Passes on messages to the ClientSideTaskHandler'''
while True:
try:
connection = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
connection.connect((server_address,port))
break
except Exception as e:
messageQueue.put(UtilityFunctions.createLogEntry('err','Unable to connect to PyComputeServer, received the following error: ' + str(e)))
time.sleep(20)
messageQueue.put(UtilityFunctions.createLogEntry('inf','Connected to PyComputeServer. ' + server_address +
':' + str(port)))
try:
#tell the server we are ready to process tasks
requestTaskMessage = UtilityFunctions.createMessage('requestTask')
UtilityFunctions.sendAll(connection,requestTaskMessage)
#begin to process tasks sent by the server
running = True
length = None
messageBuffer = ""
data = ""
while running == True:
data = connection.recv(1024)
if not data:
messageQueue.put(UtilityFunctions.createLogEntry('err',"Server sent an empty string, the connection is dead"))
break
messageBuffer += data
#the following loop allows for making sure the entire receivedMessage arrives
while True:
if length is None:
if ':' not in messageBuffer:
break
# remove the length bytes from the front of messageBuffer
# leave any remaining bytes in the messageBuffer!
length_str, ignored, messageBuffer = messageBuffer.partition(':')
length = int(length_str)
if len(messageBuffer) < length:
break
# split off the full receivedMessage from the remaining bytes
# leave any remaining bytes in the messageBuffer!
message = messageBuffer[:length]
messageBuffer = messageBuffer[length:]
length = None
# PROCESS MESSAGE HERE
serverMessage = cPickle.loads(message)
#exec('osreturn='+receivedMessage['data'])
#if osreturn == 0:
print 'executing task'
ClientSideTaskHandler.handleClientTask(messageQueue, serverMessage, resultsDirectory)
resultData = ClientSideTaskHandler.loadResult(resultsDirectory) #we expect the client has put the data in the resultsDirectory
returnMessage = UtilityFunctions.createMessage('result', data=resultData)
UtilityFunctions.sendAll(connection,returnMessage)
except Exception as e:
messageQueue.put(UtilityFunctions.createLogEntry('err',"Connection to server failed because: " + str(e) + format_exc()))
def HandleConnection(connection, clientAdress, messageQueue, taskQueue, IOLock,
numberOfConnections, numberOfConnectionsLock,
resultsDirectory):
'''Handles the connection and communication between the server and an individual client
Basic communication process:
1. EDOClient sends a 'requestTask' type message
2. EDOServer asks ServerSideTaskHandler for a Task, ServerSideTaskHandler returns a task.py and a data.zip file that have been loaded into memory. It also returns a string that identifies the task
3. EDOServer sends message to client
4. EDOServer waits for reply
5. EDOClient sends back a 'taskCompleted' type message,
6. EDOServer calls ServerSideTaskHandler.taskCompleted with the received resultComputed Message
7. EDOServer continues at step 2
If the connection to the client dies, EDOServer calls ServerSideTaskHandler.returnTask(taskid)
Args
- connection -- connection to an individual client
- clientAdress -- the address of the client
- messageQueue -- the Queue from which the logger reads
- taskQueue -- the Queue where all the tasks are located
- IOLock --
- numberOfConnections -- a multiprocessing.value which keeps track of the current number of connected clients
- numberOfConnectionsLock -- a multiprocessing.IOLock which must be aquired when wishing to modify numberOfConnections
'''
#update number of connections
numberOfConnectionsLock.acquire()
numberOfConnections.value = numberOfConnections.value + 1
numberOfConnectionsLock.release()
task = None
try:
# part of the following while loops was adapted from http://stackoverflow.com/questions/1708835/receving-socket-python
running = True
length = None #parameter telling us the length of the incoming message. Each message is message has the preamble length followed by : followed by data of length length
messageBuffer = "" # a buffer where data is stored until we've received the entire message
data = "" # the received data from the socket
while running == True:
data = connection.recv(1024)
if not data:
raise Exception("Client " + str(clientAdress) +
"sent an empty string, the connection is dead")
messageBuffer += data #add what we received to the buffer
while True:
if length is None: #if length undefined, we must wait until we've received length, we know we have once we see :
if ':' not in messageBuffer:
break
# remove the length bytes from the front of messageBuffer
# leave any remaining bytes in the messageBuffer!
length_str, ignored, messageBuffer = messageBuffer.partition(
':')
length = int(length_str)
if len(messageBuffer) < length:
break
# split off the full message from the remaining bytes
# leave any remaining bytes in the messageBuffer!
message = messageBuffer[:length]
messageBuffer = messageBuffer[length:]
length = None
# PROCESS MESSAGE HERE
receivedMessage = cPickle.loads(message)
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf',
'Received a ' + str(receivedMessage['messageType']) +
'message from client: ' + str(clientAdress)))
if receivedMessage['messageType'] == 'requestTask':
task, clientScript, data = ServerSideTaskHandler.getTask(
messageQueue, taskQueue, IOLock)
if task == None:
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf', 'Client ' + str(clientAdress) +
' requested a task, but all tasks are done'))
running = False
break
elif receivedMessage['messageType'] == 'result':
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf', 'Client ' + str(clientAdress) +
' completed his task'))
pathToReceivedResult = ServerSideTaskHandler.completeTask(
messageQueue, IOLock, task, receivedMessage['data'],
resultsDirectory)
task = None
# ServerSideResultsProcessor.processResult(messageQueue, IOLock, pathToReceivedResult)
task, clientScript, data = ServerSideTaskHandler.getTask(
messageQueue, taskQueue, IOLock)
if task == None:
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf', 'Client ' + str(clientAdress) +
' requested a task, but all tasks are done'))
running = False
break
else:
raise Exception('Received unknown message type' +
receivedMessage['messageType'])
message = UtilityFunctions.createMessage(
'task', clientScript, data)
UtilityFunctions.sendAll(connection, message)
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf',
'sent ' + str(task) + 'to ' + str(clientAdress)))
messageQueue.put(
UtilityFunctions.createLogEntry(
'inf', 'Done sending tasks to ' + str(clientAdress)))
except Exception as e:
messageQueue.put(
UtilityFunctions.createLogEntry(
'err', 'EVOServer: Connection: to ' + str(clientAdress) +
'failed because: ' + str(e) + format_exc()))
if not task == None:
ServerSideTaskHandler.returnTask(messageQueue, taskQueue, task)
finally:
numberOfConnectionsLock.acquire()
numberOfConnections.value = numberOfConnections.value - 1
numberOfConnectionsLock.release()
def HandleConnection(connection, clientAdress, messageQueue, taskQueue, IOLock, numberOfConnections, numberOfConnectionsLock, resultsDirectory):
'''Handles the connection and communication between the server and an individual client
Basic communication process:
1. EDOClient sends a 'requestTask' type message
2. EDOServer asks ServerSideTaskHandler for a Task, ServerSideTaskHandler returns a task.py and a data.zip file that have been loaded into memory. It also returns a string that identifies the task
3. EDOServer sends message to client
4. EDOServer waits for reply
5. EDOClient sends back a 'taskCompleted' type message,
6. EDOServer calls ServerSideTaskHandler.taskCompleted with the received resultComputed Message
7. EDOServer continues at step 2
If the connection to the client dies, EDOServer calls ServerSideTaskHandler.returnTask(taskid)
Args
- connection -- connection to an individual client
- clientAdress -- the address of the client
- messageQueue -- the Queue from which the logger reads
- taskQueue -- the Queue where all the tasks are located
- IOLock --
- numberOfConnections -- a multiprocessing.value which keeps track of the current number of connected clients
- numberOfConnectionsLock -- a multiprocessing.IOLock which must be aquired when wishing to modify numberOfConnections
'''
#update number of connections
numberOfConnectionsLock.acquire()
numberOfConnections.value = numberOfConnections.value+1
numberOfConnectionsLock.release()
task = None
try:
# part of the following while loops was adapted from http://stackoverflow.com/questions/1708835/receving-socket-python
running = True
length = None #parameter telling us the length of the incoming message. Each message is message has the preamble length followed by : followed by data of length length
messageBuffer = "" # a buffer where data is stored until we've received the entire message
data = "" # the received data from the socket
while running == True:
data = connection.recv(1024)
if not data:
raise Exception("Client "+str(clientAdress)+"sent an empty string, the connection is dead")
messageBuffer += data #add what we received to the buffer
while True:
if length is None: #if length undefined, we must wait until we've received length, we know we have once we see :
if ':' not in messageBuffer:
break
# remove the length bytes from the front of messageBuffer
# leave any remaining bytes in the messageBuffer!
length_str, ignored, messageBuffer = messageBuffer.partition(':')
length = int(length_str)
if len(messageBuffer) < length:
break
# split off the full message from the remaining bytes
# leave any remaining bytes in the messageBuffer!
message = messageBuffer[:length]
messageBuffer = messageBuffer[length:]
length = None
# PROCESS MESSAGE HERE
receivedMessage = cPickle.loads(message)
messageQueue.put(UtilityFunctions.createLogEntry('inf','Received a ' + str(receivedMessage['messageType']) + 'message from client: ' + str(clientAdress)))
if receivedMessage['messageType'] == 'requestTask':
task, clientScript,data = ServerSideTaskHandler.getTask(messageQueue,taskQueue,IOLock)
if task == None:
messageQueue.put(UtilityFunctions.createLogEntry('inf','Client '+str(clientAdress)+' requested a task, but all tasks are done'))
running = False
break;
elif receivedMessage['messageType'] == 'result':
messageQueue.put(UtilityFunctions.createLogEntry('inf','Client '+str(clientAdress)+' completed his task'))
pathToReceivedResult = ServerSideTaskHandler.completeTask(messageQueue,IOLock, task, receivedMessage['data'], resultsDirectory)
task = None
ServerSideResultsProcessor.processResult(messageQueue, IOLock, pathToReceivedResult)
task, clientScript,data = ServerSideTaskHandler.getTask(messageQueue,taskQueue,IOLock)
if task == None:
messageQueue.put(UtilityFunctions.createLogEntry('inf','Client '+str(clientAdress)+' requested a task, but all tasks are done'))
running = False
break;
else:
raise Exception('Received unknown message type'+receivedMessage['messageType'])
message = UtilityFunctions.createMessage('task', clientScript, data)
UtilityFunctions.sendAll(connection,message)
messageQueue.put(UtilityFunctions.createLogEntry('inf','sent ' + str(task) + 'to ' + str(clientAdress)))
messageQueue.put(UtilityFunctions.createLogEntry('inf','Done sending tasks to ' + str(clientAdress)))
except Exception as e:
messageQueue.put(UtilityFunctions.createLogEntry('err','EVOServer: Connection: to ' + str(clientAdress) + 'failed because: ' + str(e) + format_exc()))
if not task == None:
ServerSideTaskHandler.returnTask(messageQueue,taskQueue,task)
finally:
numberOfConnectionsLock.acquire()
numberOfConnections.value = numberOfConnections.value-1
numberOfConnectionsLock.release()