Sentry HDFS ACL synchronization stopped working and throws NullPointerException. The HDFS logs showed repeating errors like the following:
Arjun mentioned the reason is that some delta update from sentry server was lost, so the oldEntry at line HMSPaths.java:879 was null. That caused null exception.
There are several possible reasons why some delta changes are lost.
The fix for this issue
1. Check if oldEntry is null. If so, don't call oldEntry.moveTo. Instead, throw exception, which will be caught by its caller and causes sentry client at name node plugin gets path full snapshot from sentry server.
2. Find out why the oldEntry is null and fix it.