Attempted to run a Knime workflow with a DB Connector with a Oracle driver. I do not believe this is an issue with the driver but the error that comes up is unclear what is issue. Appreciate any insight from anybody who has tried this.
Example of the workflow:
workflow = “ParameterReading/Oracle DB Connector2”
knime.Workflow(workflow_path=workflow,workspace_path=workspace)`
Jupyter script
I run the the following code:
with knime.Workflow(workflow_path=workflow,workspace_path=workspace) as wf:
wf.execute()
The error that comes up is:
…
log4j:ERROR Could not instantiate appender named “EventCounter”.
ERROR main BatchExecutor Workflow is locked by another KNIME instance
Sep 24, 2019 2:46:12 PM org.apache.cxf.bus.osgi.CXFExtensionBundleListener unregister
INFO: Removing the extensions for bundle 158
Sep 24, 2019 2:46:12 PM org.apache.cxf.bus.osgi.CXFExtensionBundleListener unregister
INFO: Removing the extensions for bundle 159
Judging from part of your log file, real error is Workflow is locked by another KNIME meaning workflow you are calling is opened in your KNIME Analytics Platform most probably.
The workflow directory contains a file .knimeLock if it is in use and will be deleted if the workflow is closed. If want this setting can be changed.
I think @ipazin has it right – the error message suggests the workflow is locked by another running instance of KNIME. KNIME does this to prevent the workflow from being modified by one running KNIME while another is trying to use it – that is probably a good thing.
If it helps to share, I do sometimes forget to close the workflow that I am working on in KNIME before trying to run it via knimepy (in Python) and I encounter this same error message.
