ZeroMQ rrclient-broker not working - python

I am trying to run the Python and Node.JS examples from https://github.com/imatix/zguide for the client-broker-worker architecture (rrclient, rrworker, rrbroker).
I can confirm that the Python implementation works fine, and the Node.JS implementation works fine, but when I try to combine the Node.JS rrclient with the Python rrbroker, the whole thing crashes and I get the following error:
Python quit unexpectedly while using the libzmq.3.dylib plug-in.
And the broker has the following error:
Assertion failed: (prefetched_msg.flags () & msg_t::identity) == 0 (router.cpp:276)
Abort trap: 6
Seems like Node.JS has issues connecting to Python. This seems to also come up with the basic REQ/REP architecture as well, not just client-broker-worker.

Seems like re-installing pyzmq seems to fix the problem...
sudo pip uninstall pyzmq
sudo pip install pyzmq
Whew, cheers!

Related

Flask server cannot start due to the lack of libgcc

I have created flask server for my app, which I want to run on raspbian, on raspberry pi. When trying to start with flask run I've got info that libgcc_s.so.1 must be installed for pthread_cancel to work Aborted.
It looks like server has been started, but just after that it has been immediately stopped.
Tryed already to install libgcc-8-dev via apt-get install but no success.
Also found that library can be downloaded from here: https://packages.debian.org/cgi-bin/search_contents.pl?word=libgcc_s.so.1&searchmode=searchfiles&case=insensitive&version=stable&arch=i386
but I have no idea which one should I pick and how to install it properly (where to place it and how to link it)?
If you using something like openCV, then try to find out its headless version.
For me that problem was coming due to openCV. Then I install its headless version and it works fine.
Example:- sudo pip3 install opencv-python-headless

How to fix 'Install tornado itself to use zmq with the tornado IOLoop.' warning in Python

I've been following this (https://developer.ibm.com/tutorials/se-distributed-apps-zeromq-part2/) tutorial for setting up a ZeroMQ client/server setup which uses CurveZMQ to encrypt messages. The code works, however whenever I run either the client or the server it instructs me to 'Install tornado itself to use zmq with the tornado IOLoop.'
I've found that the warning appears in any file with the following import statement.
from zmq.eventloop.zmqstream import ZMQStream
I've looked in the code for zmq and noticed that it uses "minitornado", which is likely the problem, but I don't know much about tornado or how to use it.
You need to upgrade pyzmq. You can use this command to force your environment to reinstall updated version. (It worked for me!)
pip install --upgrade --force-reinstall pyzmq
I don't know if it's related to your problem. I googled about the same problem, but related to jupyter notebooks 500 internal server error, and found your question. I resolved my issue by downgrading tornado to version 5 (sudo -H pip3 install "tornado==5") and everything works again. I hope you find a solution by now or my hint helps you.

Using Flask and Jython under Windows 7

Hello everyone,
So I have been trying to use Jython to connect to an API Rest and retrieve some information. Now I want to use the Flask Framework with it. I have been trying to install the Flask with Jython but it does not seem to work at all. I am working on a Windows 7 machine and the problem for me is also that I can not download directly from the internet. For all other framework I used python wheels and installed these with Jython which worked fine.
I already tried to following commands and got these errors:
First error that I got was that it could not find the 'init.py' file in the flask folder so I changed the path in the file to the total path. But it just continued to give me more errors.
jython -m pip install '*.whl
Screenshot of the command line ouput of the error
pip install '*.whl (same as above)
I am a little stuck here and I hope that someone has an idea on how to solve this problem.
Big thanks already!!
This appears to be a bug with Jython 2.7.0. See this error report in pip and this one in Jython.
The second of those indicates that it is fixed in the 2.7.1 release candidate.

Verify thread-safety MySQLdb (Python) prior to Trac installation

I'm trying to install Trac manually for the first time. I don't want to use a one-click-installer like Bitmani, I want to learn how to install Trac manually, so I'm following the instructions carefully. I'm installing it in a Windows localhost for now, before installing it in a Linux environment.
As I follow the instructions carefully, I needed to install Python+MySQLDb, and I read this:
thread-safety is important
(...) verify that it is thread-safe by calling MySQLdb.thread_safe() from a standalone Python script (i.e., not under Apache). If the stand-alone test reports that MySQLdb is indeed thread-safe (...)
I've just installed MySQLDb 1.2.4 and I'd like to verify this. I've Googled but I haven't found an example about this, and I have no idea about Python. How can I verify if I've got a thread-safe installation?
Run this command. If you get 1 in the output, your installation is threadsafe.
python -c "import MySQLdb ; print MySQLdb.thread_safe()"

Fatal Python error after Scipy Superpack installation (Mac)

Instead of using a Python distribution, I decided to install Scipy myself and stumbled upon Scipy Superpack (http://fonnesbeck.github.io/ScipySuperpack/). After installing Python 2.7.6 I followed the instructions on the website and everything seemed to work without any problems. However, once the installation was done I received a "fatal error" message as I tried to look through my modules. More specifically, the following error:
>>> help('modules')
Please wait a moment while I gather a list of all available modules...
Fatal Python error: PyThreadState_Get: no current thread
Abort trap: 6
I receive the same error message in the terminal, as well as through IDLE. Despite the error message, I am able to import and use numpy, as well as other modules from the superpack.
I should mention that prior to installing the superpack I installed pip. However, this didn't induce the previously mentioned error.
I am very new to osx, so any advice would be greatly appreciated!
I was also having a lot of problems while trying to install all the python libraries in my mac. I searched on the web for some hours and finally got something that worked out for me.
Scipy is here as well if you want to follow this rules instead:
https://gist.github.com/audy/4012573

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