Github user phrocker commented on the issue:
https://github.com/apache/nifi-minifi-cpp/pull/134
@achristianson is the centos 7 a fresh build and did you install leveldb?
I've seen that error but when we installed leveldb the error went away and we
were able to run tests and ran about 78 instances on ec2. Let me know if you
are running from a fresh install...if not I'll spawn some more instances to
debug. Thanks---
