I’ll post this in case anyone else has the same issue and so that the KNIME developers can consider mitigations to prevent others having problems.
- I have one KNIME machine with the Columnar Backend extension and I develop a workflow using the columnar backend.
- I export that workflow.
- I have a second KNIME machine without the Columnar Backend extension. I run the workflow and it completes successfully.
- I try to save the workflow on the second KNIME machine and get errors and I am unable to save the workflow (see attached log file).
KNIME_Log_extract.txt (4.3 KB)
Note: The same behaviour can be demonstrated if a workflow is developed using the columnar backend on one machine. The workflow saved. The Columnar Extensions are uninstalled. Then KNIME restarted, the workflow loaded and reset (all nodes). Then an attempt is made to save the workflow.
Installing the Columnar Extension on the second KNIME setup fixes the problem and allows the workflow to be saved.
When a workflow created using the Columnar Backend is exported and imported to a second KNIME machine without the Columnar Extension:
- Either warn users that the workflow was developed using the columnar backend . Therefore, either warn the users that the workflow cannot be saved; or, prompt the user to install the Columnar extension.
- Change the behaviour of KNIME such that when a workflow developed with the columnar backend is imported to a machine without the columnar backend the nodes are updated so that the workflow can be saved.