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windowsconcurrencyapache-nifistartup

NiFi 1.11.4 on Windows fails to start because of an invalid concurrent tasks setting on a Processor


My problem is that Nifi won't complete its' startup. After about 40s the CMD window atarted by run-nifi.bat disappears. So the GUI doesn't connect and I cannot change the property. Anyone know if I can edit a file somewhere to change the property so that Nifi will start? If so where is the file? This is the salient line in the nifi-app.log:

org.apache.nifi.controller.serialization.FlowSynchronizationException: java.lang.IllegalArgumentException: Cannot set Concurrent Tasks to 0 for component b480dc3c-0173-1000-fd71-482c5a9f6526 because Scheduling Strategy is not Event Driven


Solution

  • @Msj I usually do not recommend doing this, but you can extract the flow.xml.gz and make modifications. Be surgically careful, if you make mistakes you can completely break the flow. Make a backup of file before working on it just in case. Repack the file when done, and make sure the permissions remain the same (chown user and chmod ).