RAID parity files are merged into HAR archives periodically. This is required to reduce the number of files that the NameNode has to track. The number of files present in a HAR archive depends on the size of HAR part files - higher the size, lower the number of files.
The size of HAR part files is configurable through the setting har.partfile.size, but that is a global setting. This task introduces a new setting specific to raid.har.partfile.size, that is used in-turn to set har.partfile.size