NetBackup 7.6.03 Master servers using Microsoft cluster services

HI,

I have deployed NetBackup 7.6.03 clustered Master servers by using Microsoft cluster services (windows 2012 R2) successfully, but my concerns are, why do we recommend NetBackup master servers to be clustered? Is it to support hardware and software failure only? Is Microsoft cluster services fully supported by NetBackup?

If any job was running during failover what is the action that should be done? will It fail or goes to waiting to retry status? 

Could anybody advise me the correct settings that should be configured to achieve this 

Regards