[TBD]ZeroMQ- Inter process messaging queue

Introduction

Laymen explanation

Technical explanation

Example

Hello World example

Hello world example

root@799633f35b75:/var/dkzeromq# cat hwserver.py

#

# Hello World server in Python

# Binds REP socket to tcp://*:5555

# Expects b"Hello" from client, replies with b"World"

#

import time

import zmq

context = zmq.Context()

socket = context.socket(zmq.REP)

socket.bind("tcp://*:5555")

while True:

# Wait for next request from client

message = socket.recv()

print("Received request: %s" % message)

# Do some 'work'

time.sleep(1)

# Send reply back to client

socket.send(b"World")

root@799633f35b75:/var/dkzeromq# python hwserver.py &

[1] 469

root@799633f35b75:/var/dkzeromq# netstat -atpun

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 6/python

tcp 0 0 0.0.0.0:5555 0.0.0.0:* LISTEN 453/python

tcp 0 0 172.17.0.12:52552 172.17.0.10:5432 ESTABLISHED 6/python

root@799633f35b75:/var/dkzeromq# cat hwclient.py

#

# Hello World server in Python

# Binds REP socket to tcp://*:5555

# Expects b"Hello" from client, replies with b"World"

#

import time

import zmq

context = zmq.Context()

socket = context.socket(zmq.REQ)

socket.connect("tcp://localhost:5555")

for request in range(10):

socket.send(b"Hello")

message = socket.recv()

print message

root@799633f35b75:/var/dkzeromq# python hwclient.py

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

Received request: Hello

World

root@799633f35b75:/var/dkzeromq#

Troubleshooting application using ZMQ

ZMQ and netstat command

Sample netstat output for ipc socket

bash-3.2# netstat -an | grep config_sock | more

ffffff01fe5045a0 stream 0 0 0 ffffff003e7413c0 0 0 /tmp/aps/ipc_sockets/config_sock

ffffff00db9b9780 stream 0 0 0 ffffff00db8692d0 0 0 /tmp/aps/ipc_sockets/config_sock

Reference

http://zguide.zeromq.org/py:all