Python Connection Timeout

[davekalpak]

KNIME Version: 4.5.1
OS: Windows Server 2019 Standard
Node: Python

Issue:
I have a python node that uploads tableau extracts to tableau online. Once in a while (not always) that node fails with:

…connection attempt timed out…consider increasing the socket timeout using VM option -Dknime.python.connecttimeout…

This error happens intermittently, sometimes the workflow is successful and sometimes it fails. When these failures occur, it is only during batch mode execution; I’ve never encountered this failure when I run the same workflow manually via KNIME GUI.

Questions:

1. Is this issue really a timeout issue, or is it related to how I am executing the workflow? I suspect it is not related to the manner of execution - since the failure is intermittent, and it sometimes does execute successfully in batch mode. However, does the default batch mode python timeout differ somehow from the GUI mode default python timeout?
2. What is the default timeout being used for python socket connections? How can I figure out what is the proper timeout amount to use? (other than trial/error, is there any information I can leverage to make an informed choice?)

Thanks!

[bruno29a]

Hi @davekalpak , it’s really a timeout issue, nothing to do with how you are running your workflow. It’s more between Knime and your Python environment. It can happen if your computer is “busy” at that moment and it takes longer to initialize your Python environment.

You can increase the timeout as suggested in the message, or keep trying again where it will be able to initialize the Python environment if it’s less “busy”.

There’s no proper timeout. It’s really up to you really, when you want it to timeout. You can set it at 2 minutes for example.

[davekalpak]

Thank you, @bruno29a.

The 2min timeout seems to have solved the issue for now, although I’m still lost as to why the machine suddenly started having this problem. There may have been some change to the environment about which I am not aware.
Similar connectivity problem appears to be happening with the Tableau Writer node very intermittently.