Thank you for your response, I really appreciate your help. I reviewed the user log and did not see a stack trace after the NPE message. Looking backward in the user log I see other log messages for the same thread and I found the endpoint being requested:
2017-01-06 17:45:44,338 INFO [NiFi Web Server-3798] org.apache.nifi.web.filter.RequestLogger Attempting request for (anonymous) GET http://servername:10000/nifi-api/flow/process-groups/e8a4ad16-1b4e-3afc-a8e0-0a2cdda95632 (source ip: ipaddress) … 2017-01-06 17:45:44,360 ERROR [NiFi Web Server-3798] o.a.nifi.web.api.config.ThrowableMapper An unexpected error has occurred: java.lang.NullPointerException. Returning Internal Server Error response.java.lang.NullPointerException: null Using Developer Tools in Chrome I compared the endpoint and it matches, here’s what Chrome indicated: GET http://servername:10000/nifi-api/flow/process-groups/e8a4ad16-1b4e-3afc-a8e0-0a2cdda95632 500 (Internal Server Error) An unexpected error has occurred. Please check the logs for additional details. send @ jquery-2.1.1.min.js:2 ajax @ jquery-2.1.1.min.js:2 u @ nf-canvas-all.js?1.1.1:45 (anonymous) @ nf-canvas-all.js?1.1.1:45 Deferred @ jquery-2.1.1.min.js:2 reload @ nf-canvas-all.js?1.1.1:45 enterGroup @ nf-canvas-all.js?1.1.1:4 (anonymous) @ nf-canvas-all.js?1.1.1:32 (anonymous) @ d3.min.js:1 Response Headers: HTTP/1.1 500 Internal Server Error Date: Fri, 06 Jan 2017 17:54:07 GMT Content-Type: text/plain Transfer-Encoding: chunked Server: Jetty(9.3.9.v20160517) Request Headers Accept: application/json, text/javascript, */*; q=0.01 Accept-Encoding: gzip, deflate, sdch Accept-Language: en-US,en;q=0.8 Connection: keep-alive Host: servername:10000 Referer: http://servername:10000/nifi/ User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36 X-Requested-With: XMLHttpRequest There is one other error that Chrome points out to me, but it might not be related. Kerberos returns an error: POST http://servername:10000/nifi-api/access/kerberos 409 (Conflict) Probably not related, but otherwise I do not see any other error that would explain what is going on with the Process Group. Regards, Kevin From: Matt Gilman [mailto:[email protected]] Sent: Thursday, January 5, 2017 5:14 PM To: [email protected] Subject: Re: NiFi UI fails to display Processor Group: NullPointerException Sorry for the inconvenience. Is there a stack trace listed in the user log? A quick glance at the code and the error handler looks like it logs the exception (which should include the stack trace) unconditionally. Also, you should be able to look backward from that line to look for other log messages for the same thread 'NiFi Web Server-299' to see which endpoint was being invoked. Sounds like the endpoint is going to be the one that returns that nest Process Group but just to be sure. Additionally, you can verify that by checking the develop tools in your browser to see which requestion failed. If there is a stack trace following the NPE message, that would be helpful. Thanks. Matt On Thu, Jan 5, 2017 at 7:47 PM, Kevin Verhoeven <[email protected]<mailto:[email protected]>> wrote: After updating from NiFi 1.0 to 1.1.1, I am unable to browse into one or more of my Processor Groups. The UI seems to work until I double click on a specific Processor Group, then the UI throws an error “An unexpected error has occurred” and I find the following in the nifi-user.log log file: 2017-01-05 22:29:15,886 INFO [NiFi Web Server-19] org.apache.nifi.web.filter.RequestLogger Attempting request for (anonymous) GET http://servername:10000/nifi-api/flow/process-groups/e8a4ad16-1b4e-3afc-a8e0-0a2cdda95632 (source ip: ipaddress) 2017-01-05 22:29:16,397 INFO [NiFi Web Server-305] org.apache.nifi.web.filter.RequestLogger Attempting request for (anonymous) GET http:// servername:10000/nifi-api/flow/current-user (source ip: ipaddress) … 2017-01-05 22:29:16,402 ERROR [NiFi Web Server-299] o.a.nifi.web.api.config.ThrowableMapper An unexpected error has occurred: java.lang.NullPointerException. Returning Internal Server Error response. java.lang.NullPointerException: null … 2017-01-05 22:29:16,408 INFO [NiFi Web Server-305] org.apache.nifi.web.filter.RequestLogger Attempting request for (anonymous) GET http:// servername:10000/nifi-api/flow/controller/bulletins (source ip: 10 ipaddress) 2017-01-05 22:29:16,821 INFO [NiFi Web Server-19] org.apache.nifi.web.filter.RequestLogger Attempting request for (anonymous) GET http:// servername:10000/nifi-api/site-to-site (source ip: ipaddress) Any advice on how to proceed? Thanks, Kevin
