@sirisha A
Work-preserving ResourceManager restart ensures that applications continuously function during a ResourceManager restart with minimal impact to end-users.
The overall concept is that the ResourceManager preserves application queue state in a pluggable state store, and reloads that state on restart. While the ResourceManager is down, ApplicationMasters and NodeManagers continuously poll the ResourceManager until it restarts.
If you have automatic failover enabled true then this polling time will get reduced and your jobs will resume in short amount of time so I would suggest to have both the options true in the configuration.
Hope this information helps.