Is it necessary to install HDFS cluster in advance to add sentry service in Cloudera

[#1]

When CDH cluster adds sentry service, an error appears in the above picture, indicating that HDFS or core configuration is required (but this service also needs to be configured with core.defaultFs). I want to know whether HDFS is generally necessary for sentry service, but I don't see relevant  instructions (Prerequisites) on the official website (Before You Install Sentry | 6.3.x | Cloudera Documentation). Can anyone help provide relevant documents?  because I need to convince customers that HDFS is necessary.  Thankssss!!!

[#2 · Accepted solution]

@wenzf Yes, Sentry Stores some info in HDFS I believe. Take a look of below doc which talks about architecture. 

https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/sg_sentry_overview.html#sentry_overv...

https://cwiki.apache.org/confluence/display/SENTRY/Sentry+Tutorial

[#3]

Thank you very much for your answer, but another question is that I need a clear evidence to convince customers that HDFS is necessary when adding Apache sentry service. Can you help find the relevant documents here?

Sorry for the inconvenience.