Today I encountered an error with NiFi that I have never seen before. We have been successfully running NiFi, managed by Ambari, for a number of months now. This morning while working in NiFi, the UI suddenly died. When refreshing the UI, I get ERR_CONNECTION_REFUSED. I have tried this in both Chrome and Explorer, so it is not a browser specific issue.
I have now spent the morning trying to solve this issue. I can give the following info:
I have restart NiFi a number of times trying to solve this, but this has no effect. Any help would be greatly appreciated.
My problem went away on it's own strangely. I left it without restarting and about 5 hours after the most recent restart everything was back to normal. For some reason the start up was very slow. Since then I've had to restart once, and that was quick. Sorry I can't help.