I am working on a project where we need to use Hbase and Nifi. We like the monitoring/ ease of use Ambari provides. But the version of Nifi that we need to use is 1.4. Currently only version 1.2 of Nifi is part of the HDF management pack. I was just looking for suggestions on the best way to tackle this issue in order for Ambari to still be able to manage Nifi 1.4.0. Do I not even bother with the HDF management pack and just install Nifi as a custom service?
Until Hortonworks supports Nifi 1.4 and publishes a new management pack for the new version, your only option is to create your own management pack. One way Hortonworks provide value to its Enterprise customers is to make sure that all parts of a version are tested together - integration testing. If you upgrade one component from let's say HDF 3.0 then that creates a risk from support stand point. Since everything Hortonworks does is open source, you can just create your own management pack and manage new version of Nifi from Ambari.
https://cwiki.apache.org/confluence/display/AMBARI/Management+Packs -->how to create management pack.