I have a 3-node cluster with openjdk11. When I restarted the NiFi nodes, it had the following NullPointerException. However, if I update JAVA_HOME to Java8 for all nodes. The error couldn't be reproduced any more.
The first thing to check is if your version of the platform supports your version of OpenJDK.
For instance, if you are on HDF 3.5 or below, then OpenJDK does not appear to be supported: https://supportmatrix.hortonworks.com/
However, if you are on the latest Flow Management version in CDP, then OpenJDK 11.0.8 and above should be fine, as per https://docs.cloudera.com/cfm/2.0.4/support-matrix/topics/cfm-system-requirements.html
If you confirmed that you are within the right combination of platform and JDK version and the problem still persists I would recommend to log a support ticket (I did not find other occurances of this error).
Thanks for the reply. I don't think I used HDF. I just installed the nifi 1.12.1 binary into three physical machines.
This is more likely an issue in the specific Java 11 version your are using.
Somethings you may want to try:
1. Try a different update version of Java 11
2. add the following line to the NiFi bootstrap.conf file:
java.arg.<some unused number>=-Djava.locale.providers=COMPAT
Note: A restart of NiFi is needed with any config file change except logback.xml.
Hope this helps,