473,382 Members | 1,766 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,382 software developers and data experts.

Trying to Send Repeated Messages to a Server Using sockets

Hey Everyone, I am trying to send repeated messages from a "Node" to a
"Server". It works the first time I send the from the Node to Server,
but after that it either errors, or does not do anything.

I would love some help, here is the code:

import socket
import thread
import time
def Node(nodeAddress):

'''connect to node and get its file load'''

sN = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Echo client program
HOST = nodeAddress # The remote host
PORT = 50007 # The same port as used by the server
sN = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sN.connect((HOST, PORT))
sN.send('Hello, world')
data = sN.recv(1024)
sN.close()
print 'Received', repr(data)

def Server(address):

''' starts a socket server and decides what to do with incomming
stuff'''
message = "hello from server"
HOST = '' # Symbolic name meaning the local host
PORT = 50007 # Arbitrary non-privileged port
sP = None
sL = None
sR = None
sS = None
sStor = 0
sTotalStorage = 0
sCT = (sP,)
'''look in server.conf for connect_to_server value'''

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
print message
time.sleep(1)
data = conn.recv(1024)
#if not data: break
conn.send(data)
conn.close()

thread.start_new(Server,('',))
thread.start_new(Node,('127.0.0.1',))
while 1:
time.sleep(5)
thread.start_new(Node,('127.0.0.1',))

Oct 16 '07 #1
1 2712
danfolkes a écrit :
Hey Everyone, I am trying to send repeated messages from a "Node" to a
"Server". It works the first time I send the from the Node to Server,
but after that it either errors, or does not do anything.

I would love some help, here is the code:
Posting the trackbacks may have help too.
import socket
import thread
import time
def Node(nodeAddress):
pep08:
- function names should be all_lower. MixedCase is for class names.
- variable names should be all_lower
'''connect to node and get its file load'''

sN = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Echo client program
HOST = nodeAddress # The remote host
PORT = 50007 # The same port as used by the server
These two last lines are useless here. The second would be meaningful
outside the function's body. The first one looks like a constant, but is
only an alias for the nodeAddress param.
sN = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
This discards the first socket instanciated above...
sN.connect((HOST, PORT))
sN.send('Hello, world')
data = sN.recv(1024)
sN.close()
print 'Received', repr(data)

def Server(address):
pep08 again.
''' starts a socket server and decides what to do with incomming
stuff'''
message = "hello from server"
HOST = '' # Symbolic name meaning the local host
PORT = 50007 # Arbitrary non-privileged port
Idem. But this time, you just don't use the 'address' param...
sP = None
sL = None
sR = None
sS = None
sStor = 0
sTotalStorage = 0
sCT = (sP,)
None of those very badly named variables are used in the code.
'''look in server.conf for connect_to_server value'''

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
Hem...
print 'Connected by', addr
while 1:
print message
time.sleep(1)
data = conn.recv(1024)
#if not data: break
conn.send(data)
Your server loops forever on the first connection it got...

conn.close()

thread.start_new(Server,('',))
thread.start_new(Node,('127.0.0.1',))
while 1:
time.sleep(5)
thread.start_new(Node,('127.0.0.1',))
Here's a somewhat corrected version. I'm not sure it's an example to
follow wrt/ threaded server implementation (it's the first time I write
one myself), but at least it works.

import socket
import thread
import time

HOST = ''
PORT = 50007

def node(host, num):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, PORT))
print "node %s: sending" % num
s.send("node '%s' says : Hello, world" % num)
time.sleep(10) # play with this to see how the server reacts...
print "node %s: receiving" % num
data = s.recv(1024)
s.close()
print "node %s: received '%s'" % (num, data)
print "node %s: done" % num
def server(address):
thread_ids = []

def handle(conn, addr):
tid = thread.get_ident()
print "server (handle %s): handling connection for %s" % (tid,
str(addr))

print "server (handle %s): receiving" % tid
data = conn.recv(1024)
while data:
print "server (handle %s): got '%s'" % (tid, data)
print "server (handle %s): sending '%s'" % (tid, data)
conn.send(data)
time.sleep(2)
print "server (handle %s): receiving" % tid
data = conn.recv(1024)

print "server (handle %s): no more data for %s, closing" %
(tid, str(addr))
conn.close()
thread_ids.remove(tid)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(10)

while 1:
print "server: active handler threads : %s" % thread_ids
nb_handlers = len(thread_ids)
while nb_handlers 10:
print "server: too much connections, waiting for current
handlers to terminate"
time.sleep(5)
nb_handlers = len(thread_ids)

print "server: accepting connections - actually %s handlers" %
nb_handlers
conn, addr = s.accept()
print "server: connected by", addr
print "server: starting a new handler thread for connection %s"
% nb_handlers
thread_ids.append(thread.start_new(handle, (conn, addr)))
time.sleep(1)

def main():
print "starting server..."
thread.start_new(server,('',))

num = 1
while 1:
time.sleep(1)
print "new node %s..." % num
thread.start_new(node,('127.0.0.1',num))
num += 1

if __name__ == '__main__':
main()
Oct 16 '07 #2

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

1
by: Steve | last post by:
Please take a look at the simple code segment below and advise me what is wrong. According to the help and examples I've seen it should work unless I misunderstand something. The problem is...
1
by: Kueishiong Tu | last post by:
How do I send and receive internet messages using socket in the .net VC++ environment? Coding sample will be helpful.
5
by: zorhel | last post by:
Hi. My clients will be IE, Mozilla and Opera in a Windows and *nix OS. So, my web app need to, from a server, send messages to a specific client (browser), send messages for all clients,...
11
by: hazz | last post by:
smtpClient.Send(message) is causing me problems as per specifics in the trace below. Email is sent but not without this error typically upon sending the second email, but sometimes when running...
3
by: growse | last post by:
Right, I've got a 2 c# programs here. Lets call them A and B. My aim is to send a simple string from B to A. A is always running. I've overridden the WndProc method to give me messages that are...
2
by: SammyBar | last post by:
Hi all, I'm trying to send a message from ASP.NET to another PC by using MSMQ. I created my ASP.NET project by using Visual Studio 2005 but I initially set the project to be located on the File...
14
by: eliss.carmine | last post by:
I'm using TCP/IP to send a Bitmap object over Sockets. This is my first time using C# at all so I don't know if this is the "right" way to do it. I've already found out several times the way I was...
1
by: kirany82 | last post by:
I want to write a server such that it receives UDP and TCP messages on same port continuously. I have created 2 sockets tcpsock, udpsock. I am binding them to same port by using (setsockopt(sock,...
7
by: John Straumann | last post by:
Hi all: I am trying to write some code to send an email from an Assembly file, and found some examples on MSDN. However when I run the program (I am using a console app for testing), the email...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 3 Apr 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome former...
0
by: ryjfgjl | last post by:
In our work, we often need to import Excel data into databases (such as MySQL, SQL Server, Oracle) for data analysis and processing. Usually, we use database tools like Navicat or the Excel import...
0
by: taylorcarr | last post by:
A Canon printer is a smart device known for being advanced, efficient, and reliable. It is designed for home, office, and hybrid workspace use and can also be used for a variety of purposes. However,...
0
by: aa123db | last post by:
Variable and constants Use var or let for variables and const fror constants. Var foo ='bar'; Let foo ='bar';const baz ='bar'; Functions function $name$ ($parameters$) { } ...
0
by: ryjfgjl | last post by:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
0
BarryA
by: BarryA | last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.