Unable to start or stop a process in NiFi

[#1]

I stopped a running process in NiFi 0.4.1 to make a configuration change, but I am unable to make an edit or re-start the process. It seem stuck waiting for a thread to finish. How do I debug this situation? I've looked at nifi-app.log, searched for that process name, but did not see anything of value. I ran ps -eLf hoping to see a thread with Solr in the name, but I didn't find that either. Here is a picture showing the lack of a "start" or "edit configuration" options.

What else can I do to troubleshoot this problem before restarting the nifi process on this machine?

[#2]

Vlad, at this point please go into NiFi's bin directory and execute nifi.sh dump command. Send those logs through.

[#3 · Accepted solution]

Thanks for reporting it and for providing the stack traces. Very helpful. I've filed an Apache NiFi JIRA for it https://issues.apache.org/jira/browse/NIFI-1417