if i use one CommandGenerator to request same ip twice, first time the timeout is 0, second time the timeout is 60, all result is "No SNMP response received before timeout", seems the second time's timeout not worked.
create CommandGenerator every time or request different ip will get correct result.
I am sure that timeout has passed to UdpTransportTarget, below is my part code:
_cmdgen = cmdgen.CommandGenerator()
import time
try:
#a = get_cmdgen()
start_time = time.time()
worker = SNMP(
"1.1.1.",
"public",
logger=logging,
port=161,
timeout=0,
retries=0,
device_info=device_info,
model_version=1
)
output = worker.bulk_get(_cmdgen,["1.3.6.1.2.1.1.1.0"])
print output
except Exception as e:
print str(e)
finally:
endtime = time.time()
print (endtime-start_time)
try:
#a = get_cmdgen()
start_time = time.time()
worker1 = SNMP(
"1.1.1.1",
"public",
logger=logging,
port=161,
timeout=60,
retries=0,
device_info=device_info,
model_version=1
)
output = worker1.bulk_get(_cmdgen,["1.3.6.1.2.1.1.1.0"])
print output
except Exception as e:
print str(e)
finally:
endtime1 = time.time()
print (endtime1-start_time)
Related
output printing the len of arrival and service timesI am trying to implement an M/M/1 markovian process with exponential inter arrival and exponential service times using simpy. The code runs fine but I dont quite get the expected results. Also the number of list items in arrival times is lesser than the number of list items in service time after the code is run.
# make a markovian queue
# make a server as a resource
# make customers at random times
# record the customer arrival time
# customer gets the resource
# record when the customer got the resource
# serve the customers for a random time using resource
# save this random time as service time
# customer yields the resource and next is served
import statistics
import simpy
import random
arrival_time = []
service_time = []
mean_service = 2.0
mean_arrival = 1.0
num_servers = 1
class Markovian(object):
def __init__(self, env, num_servers):
self.env = env
self.servers = simpy.Resource(env, num_servers)
#self.action = env.process(self.run())
def server(self,packet ):
#timeout after random service time
t = random.expovariate(1.0/mean_service)
#service_time.append(t)
yield self.env.timeout(t)
def getting_service(env, packet, markovian):
# new packet arrives in the system
arrival_time = env.now
with markovian.servers.request() as req:
yield req
yield env.process(markovian.server(packet))
service_time.append(env.now - arrival_time)
def run_markovian(env,num_servers):
markovian = Markovian(env,num_servers)
packet = 0
#generate new packets
while True:
t = random.expovariate(1.0/mean_arrival)
arrival_time.append(t)
yield env.timeout(t)
packet +=1
env.process(Markovian.getting_service(env,packet,markovian))
def get_average_service_time(service_time):
average_service_time = statistics.mean(service_time)
return average_service_time
def main():
random.seed(42)
env= simpy.Environment()
env.process(Markovian.run_markovian(env,num_servers))
env.run(until = 50)
print(Markovian.get_average_service_time(service_time))
print (arrival_time)
print (service_time)
if __name__ == "__main__":
main()
Hello there were basically one bug in your code and two queuing theory misconceptions:
Bug 1) the definition of the servers were inside the class, this makes the model behaves as a M/M/inf not M/M/1
Answer: I put the definition of your resources out the the class, and pass the servers not the num_servers from now on.
Misconception 1: with the times as you defined:
mean_service = 2.0
mean_arrival = 1.0
The system will generate much more packets and it is able to serve. That's why the size of the lists were so different.
Answer:
mean_service = 1.0
mean_arrival = 2.0
Misconception 2:
What you call service time in your code is actually system time.
I also put some prints in your code so we could see that is doing. Fell free to comment them. And there is no need for the library Statistics, so I commented it too.
I hope this answer is useful to you.
# make a markovian queue
# make a server as a resource
# make customers at random times
# record the customer arrival time
# customer gets the resource
# record when the customer got the resource
# serve the customers for a random time using resource
# save this random time as service time
# customer yields the resource and next is served
#import statistics
import simpy
import random
arrivals_time = []
service_time = []
waiting_time = []
mean_service = 1.0
mean_arrival = 2.0
num_servers = 1
class Markovian(object):
def __init__(self, env, servers):
self.env = env
#self.action = env.process(self.run())
#def server(self,packet ):
#timeout after random service time
# t = random.expovariate(1.0/mean_service)
#service_time.append(t)
# yield self.env.timeout(t)
def getting_service(env, packet, servers):
# new packet arrives in the system
begin_wait = env.now
req = servers.request()
yield req
begin_service = env.now
waiting_time.append(begin_service - begin_wait)
print('%.1f Begin Service of packet %d' % (begin_service, packet))
yield env.timeout(random.expovariate(1.0/mean_service))
service_time.append(env.now - begin_service)
yield servers.release(req)
print('%.1f End Service of packet %d' % (env.now, packet))
def run_markovian(env,servers):
markovian = Markovian(env,servers)
packet = 0
#generate new packets
while True:
t = random.expovariate(1.0/mean_arrival)
yield env.timeout(t)
arrivals_time.append(t)
packet +=1
print('%.1f Arrival of packet %d' % (env.now, packet))
env.process(Markovian.getting_service(env,packet,servers))
def get_average_service_time(service_time):
average_service_time = statistics.mean(service_time)
return average_service_time
def main():
random.seed(42)
env= simpy.Environment()
servers = simpy.Resource(env, num_servers)
env.process(Markovian.run_markovian(env,servers))
env.run(until = 50)
print(Markovian.get_average_service_time(service_time))
print ("Time between consecutive arrivals \n", arrivals_time)
print("Size: ", len(arrivals_time))
print ("Service Times \n", service_time)
print("Size: ", len(service_time))
print ("Waiting Times \n", service_time)
print (waiting_time)
print("Size: ",len(waiting_time))
if __name__ == "__main__":
main()
This is a code which is given to us by our teacher for using in our homework. There should't have been an error. But there is. Please help me fix it. (The error is in line9)
import socket
serverPort = 12000
serverSocket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
serverSocket.bind(('',serverPort))
serverSocket.listen(1)
print ("The server is ready to receive")
while 1:
connectionSocket, addr = serverSocket.accept()
byte_sentence = connectionSocket.recv(1024)
utf_sentence = byte_sentence.decode("utf-8")
modified_utf_sentence = utf_sentence.upper()
modified_byte_sentence = bytes(modified_utf_sentence, "utf-8")
connectionSocket.send(modified_byte_sentence)
connectionSocket.close()
File "tcpserver.py", line 9
connectionSocket, addr = serverSocket.accept()
^
IndentationError: expected an indented block
You need to indent your code by 4 spaces after you declare your while loop.
import socket
serverPort = 12000
serverSocket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
serverSocket.bind(('',serverPort))
serverSocket.listen(1)
print ("The server is ready to receive")
while 1:
connectionSocket, addr = serverSocket.accept()
byte_sentence = connectionSocket.recv(1024)
utf_sentence = byte_sentence.decode("utf-8")
modified_utf_sentence = utf_sentence.upper()
modified_byte_sentence = bytes(modified_utf_sentence, "utf-8")
connectionSocket.send(modified_byte_sentence)
connectionSocket.close()
everything in the while loop must be indented by 4 spaces. Returning to unindented code terminates the while looop.
I wrote an IP and port scanning program and I want to take the captured data and output it to a text file. I've been trying to figure it out for a while and haven't had any luck applying what I can find in searches. At the end, I commented out how I thought it should work to write the information to a file.
Any help or suggestions would be greatly appreciated, I'm still somewhat new to Python and trying to learn.
#!/usr/bin/env python
import ipaddress
import sys, time
import os
import subprocess
import socket
from datetime import datetime
FNULL = open(os.devnull, 'w')
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
print ('Welcome to the IP/Port Scanner and Logger')
address = input('Enter starting IP address: ')
split1 = first,second,third,fourth = str(address).split('.')
start = int(fourth)
host = first+'.'+second+'.'+third+'.'+str(start)
end_address = input('Enter the ending IP address: ')
split2 = first,second,third,fourth = str(end_address).split('.')
end = int(fourth)
network = first+'.'+second+'.'+third+'.'
min_port = input("Enter starting port range: ")
max_port = input("Enter ending port range: ")
remoteserver = host
remoteserverIP = socket.gethostbyname(remoteserver)
def port_scan():
print ('Port scanning function initialized:')
try:
for port in range(int(min_port),int(max_port)):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
result = sock.connect_ex((remoteserverIP, port))
if result == 0:
print ('Port ' + str(port) + ': Open')
sock.close()
except KeyboardInterrupt:
print ("You halted the process")
sys.exit()
except socket.gaierror:
print ('Hostname could not be resolved. Exiting')
sys.exit()
except socket.error:
print ("Couldn't connect to server")
sys.exit()
return port
def check_up():
for ip_address in range(int(start), int(end)):
try:
subprocess.check_call(['ping', '-c', '2',
network + str(ip_address)],
stdout=FNULL,stderr=FNULL)
except (OSError, subprocess.CalledProcessError):
print ("{}{}".format(network,ip_address), "is down")
except KeyboardInterrupt:
print ("You halted the process")
sys.exit()
else:
print ("{}{}".format(network,ip_address), "is up")
return ip_address
check_up()
time1 = datetime.now()
time2 = datetime.now()
scantime = time2-time1
print ('Scan completed in: ', scantime)
while True:
print ('Would you like to write information to file?')
answer = input()
if answer in ['yes', 'y', 'yeah']:
print ('Alright, writing to file')
print ('Program will exit upon scan completion.')
break
elif answer in ['no', 'n']:
print ('Okay, exiting now..')
sys.exit()
break
else:
print ('Please enter a yes or no value')
###Output File
##with open('ipscan.txt', 'w+') as ip:
## print (ip_address, port)
##
##sys.exit()
I am writing a python code to find throughput between server and client. It is based on speedtest.net functionality where I am sending a dummy file to calculate the speed. The problem I am facing is unreliable throughput output. I will appreciate your suggestions on the same. Here is the code.
server.py
import socket
import os
port = 60000
s = socket.socket()
host = socket.gethostname()
s.bind((host, port))
s.listen(5)
print 'Server listening....'
while True:
conn, addr = s.accept()
print 'Got connection from', addr
data = conn.recv(1024)
print('Server received', repr(data))
filename='akki.txt'
b = os.path.getsize(filename)
f = open(filename,'rb')
l = f.read(b)
while (l):
conn.send(l)
l = f.read(b)
f.close()
print('Done sending')
conn.send('Thank you for connecting')
conn.close()
Client.py
import socket
import time
import os
s = socket.socket()
host = socket.gethostname()
port = 60000
t1 = time.time()
s.connect((host, port))
s.send("Hello server!")
with open('received_file', 'wb') as f:
print 'file opened'
t2 = time.time()
while True:
data = s.recv(1024)
if not data:
break
f.write(data)
t3 = time.time()
print data
print 'Total:', t3 - t1
print 'Throughput:', round((1024.0 * 0.001) / (t3 - t1), 3),
print 'K/sec.'
f.close()
print('Successfully received the file')
s.close()
print('connection closed')
Output when sending akki.txt
Server Output
Server listening....
Got connection from ('10.143.47.165', 60902)
('Server received', "'Hello server!'")
Done sending
Client output
file opened
Raw timers: 1503350568.11 1503350568.11 1503350568.11
Total: 0.00499987602234
**Throughput: 204.805 K/sec.**
Successfully received the file
connection closed
Output for ak.zip ( which is bigger file)
Client output
file opened
Total: 0.0499999523163
**Throughput: 20.48 K/sec.**
Successfully received the file
connection closed
Short Answer: you need to take the file size into consideration.
More Details:
Throughput is data/time. Your calculation:
round((1024.0 * 0.001) / (t3 - t1), 3)
Doesn't take the file size into account. Since sending a large file takes more time, 't3-t1' is bigger so your throughput is smaller (same numerator with larger denominator). Try adding the file size to the formula and you should get much more constant results.
Hope this helps.
I have the below code that i am trying the run using python3.2 interpreter.
import socket #for sockets
import sys #for exit
#from UserString import MutableString
#create an INET, STREAMing socket
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error:
print ('Failed to create socket')
sys.exit()
print ('Socket Created')
host = 'www.google.com';
port = 80;
try:
remote_ip = socket.gethostbyname( host )
except socket.gaierror:
#could not resolve
print ('Hostname could not be resolved. Exiting')
sys.exit()
#Connect to remote server
s.connect((remote_ip , port))
print ('Socket Connected to ' + host + ' on ip ' + remote_ip)
#Send some data to remote server
message = "GET / HTTP/1.0\r\n\r\n"
try :
#Set the whole string
s.sendall(message.encode())
except socket.error:
#Send failed
print ('Send failed')
sys.exit()
print ('Message send successfully')
#Now receive data
messageParts = []
remaining = 4096
chunk = s.recv(remaining)
messageParts.append(chunk)
while (len(chunk) > 0):
chunk = s.recv(remaining)
messageParts.append(chunk.decode())
finalMessage = b"".join(messageParts)
print('Printing the html contents ...')
print(finalMessage)
Upon running the above code, with python version 3.2, i get the below error:
Socket Created
Socket Connected to www.google.com on ip 74.125.201.147
Message send successfully
Traceback (most recent call last):
File "TestMainServerV2.py", line 73, in <module>
finalMessage = b"".join(messageParts)
TypeError: sequence item 1: expected bytes, str found
Could anybody let me know what is the issue?
Thanks!
messageParts.append(chunk.decode())
is appending strs to messageParts.
chunk = s.recv(remaining)
messageParts.append(chunk)
is appending bytes to messageParts. (Everything that comes through a socket is bytes so chunk is a bytes object.)
Especially in Python3, one should never mix strs and bytes.
b"".join(messageParts)
raises a TypeError since b"".join expects only bytes.
You can avoid the problem by not decoding chunk. Use
messageParts.append(chunk)
instead of
messageParts.append(chunk.decode())