Python / Twisted matrix and SOAP threading - python

I have an application built with Python / Twisted Matrix which uses methods from a SOAP client in order to send some messages. Problem is that sometimes i want to send a lot of messages and when that happens i would like to do it in multiple threads. For example if i have to send 100 messages i would like this broken into groups of 20 messages and to create 5 threads to send the messages in parallel.
What should i look for ? Any ideas ? I would also like the threads to be able to report back with the gathered data
P.S. given the fact that probably working with SOAP clients is more of a problem of waiting around ... do you think that threading is not the best approach to solve this ? Can the callbacks of the soap client be used to create some sort of "pool" of senders and have the senders somehow as for new stuff to send as soon as they are free ? Ideas ?

The best approach is probably defined by the distribution of the SOAP services and methods your accessing.
My first suggestion would be to not use OS Threading, but use micro-threading generator-coroutines with inlineCallbacks and deferredSemaphores.
But you might want to tune things to reuse connections for the same server and/or retain server cookies.

Related

Concurrency test of UDP server

I need to write a script to stress test the UDP server.It needs to simulate about 5000 online users and about 400 concurrent users.I couldn't find a similar function on Google, so I wrote a UDP client myself.But I had a problem simulating multiple clients.The solution I came up with:
One socket per client
How to mark online users and concurrent users when using multithreading and multiple sockets to simulate clients?
I encapsulate the client into classes,in this class __ init__ The method of adding one to a variable is used to record the of online users.In this way, concurrent operations cannot be performed successfully
Is it feasible to create 5000 sockets with threads? Is this a best practice? Good performance?
Other approaches?
Is there another approach I haven't thought of? Am I on the wrong track?
Is there a mature testing framework that can be used for reference?
Finally, English is not my mother tongue. Please forgive me for my typos or grammar.Thank you for your reading and look forward to your reply.
There is Apache JMeter tool which is free, open source and modular
There is UDP Request sampler plugin which adds support of the UDP protocol to JMeter, see
The "5000 online users and 400 concurrent users" requirement may be interpreted in the following manner: real users don't hammer the system under test non-stop, they need some time to "think" between operations, i.e. read text, type response, fill forms, take a phone call, etc. So you need to introduce realistic think times using JMeter Timers so you could come up with the configuration when:
5000 users are "online" (connected to the server)
4600 are not doing anything, just "sleeping"
400 are actively sending requests
As long as your machine is capable of doing this without running out of CPU, RAM, Network, etc - it should be fine, personally I would use something like greenlet

select() function for simultaneously I/O

I am trying to implement a multi-threading server which can handle with simultaneously read/write from client.
The server method:
The client connects to the server, when each message starts with the name of the user they want to send the message to, followed by '|'. It looks something like that: "USER_NAME|DATA".
After receiving the data, the server knows by a dictionary of {socket:username} where to send the data. Everything works great, except the fact that the client can't handle with simultaneously reading and writing. I searched for a method to handle that and i found the select() function, but with a lack of examples- i couldn't integrate that function in my code.
therefore I have 2 questions:
Is the select() function should be on the server side? will it be more efficient?
Is someone can demonstrate with a simple example how the select() method should look in the client side?
Thanks in advance!!!
Though select() will work, you have to use threads if you want to do other things while the system is blocked on the select.
Have a look at glib's GIO library. There you can connect callbacks to the actions you want to monitor or act on, for example the 'connect's from clients.
Just open a socket, and use its file descriptor to hang a gio.add_watch on. Here's a mini-tutorial on using giochannels.

Python tcp socket client

I need to have a tcp socket client connected to a server to send data and receive.
But this socket must be always on and i cannot open another socket.
I have always some data to send over the time and then later process the answer to the data sent previously.
If i could open many sockets, i think it was more easy. But in my case i have to send everything on the same socket asynchronously.
So the question is, what do you recommend to use within the Python ecosystem? (twisted, tornado, etc)
Should i consider node.js or another option?
I highly recommend Twisted for this:
It comes with out-of-the-box support for many TCP protocols.
It is easy to maintain a single connection, there is a ReconnectingClientFactory that will deal with disconnections and use exponential backoff, and LoopingCall makes it easy to implement a heartbeat.
Stateful protocols are also easy to implement and intermingle with complex business logic.
It's fun.
I have a service that is exactly like the one you mention (single login, stays on all the time, processes data). It's been on for months working like a champ.
Twisted is possibly hard to get your head around, but the tutorials here are a great start. Knowing Twisted will get you far in the long run!
"i have to send everything on the same socket asynchronously"
Add your data to a queue, have a separate thread taking items out of the queue and sending via socket.send()

Python Socket Programming

I am developing a testbed for cloud computing environment. I want to establish multiple client connection to a server. What I want is that, server first of all send a data to all the clients specifying sending_interval and then all the clients will keep on sending their data with a time gap of that time_interval (as specified by the server). Please help me out, how can I do the same using python socket program. (i.e. I want multiple client to single server connectivity and also client sending data with the time gap specified by server). Will be great-full if anyone can help me. Thanks in advance.
This problem is easily solved by the ZeroMQ socket library. It is production stable. It allows you to define publisher-subscriber relationships, where a publishing process will publish data on a port regardless of how many (0 to infinite) listening processes there are. They call this the PUB-SUB model; it's in their docs (link below).
It sounds like you want to set up a bunch of clients that are all publishers. They can subscribe to a controlling channel, which which will send updates to their configuration (how often to write). They also act as publishers, pushing out their own data at an interval specified by default/config channel/socket.
Then, you have one or more listening processes that listen to all the clients' published messages. Perhaps you could even have two listening processes, one for backup or DR, or whatever.
We're using ZeroMQ and loving the simplicity it gives; there's no connection errors because the publisher doesn't care if anyone is listening, and the subscriber can start before the publisher and if there's nothing there to listen to, it can just loop around and wait until there is.
Bindings are available in ALL languages (it's freaky). The Python binding isn't pure-python, it does require a C compiler, but is frighteningly fast, and the pub/sub example is a cut/paste, 'golly, it works!' experience.
Link: http://zeromq.org
There are MANY other methods available with this library, including message queues, etc. They have relatively complete documentation, too.
Multi-Client and Single server Socket programming can be achieved by Multithreading in Socket Programming. I have implemented both the method:
Single Client and Single Server
Multiclient and Single Server
In my GitHub Repo Link: https://github.com/shauryauppal/Socket-Programming-Python
What is Multi-threading Socket Programming?
Multithreading is a process of executing multiple threads simultaneously in a single process.
To understand well you can visit Link: https://www.geeksforgeeks.org/socket-programming-multi-threading-python/, written by me.

Interprocess messaging between two Python programs

We have two Python programs running on two linux servers. Now we want to send messages between these Python programs. The best idea so far is to create a TCP/IP server and client architecture, but this seems like a very complicate way to do it. Is this really best practice for doing such a thing?
I like zeromq for simple messaging, it's really lightweight and fast...very flexible as well. Using AMQP messaging isn't a bad idea either depending on the specifics of your situation, I've found kombu to be a very nice pythonic library for that. You could also use xmlrpclib or setup a simple REST API with bottle or flask. Every option has it's place, so I'd investigate all your options.
This really depends on the kind of messaging you want and the roles of the two processes. If it's proper "client/server", I would probably create a SimpleHTTPServer and then use HTTP to communicate between the two. You can also use XMLRPCLib and the client to talk between them. Manually creating a TCP server with your own custom protocol sounds like a bad idea to me. You might also consider using a message queue system to communicate between them.
You could have a mulitprocessing.managers. As doc says :"A manager object controls a server process which manages shared objects. Other processes can access the shared objects by using proxies."
In your case, you could create a master process that control your other processes, each of those processes will call the master to grab the data.

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