Log Aggregation File Controllers
By default, log aggregation supports two file controllers, TFile and IFile. You can also add your own custom file controller.
TFile is the legacy file controller in YARN. It is reliable and well tested. Its buffer and chunk sizes are configurable. It deletes the log files during rolling sessions, meaning that long running applications do not store all of their logs locally. However, it creates a single file for each log aggregation session.
Named metadata blocks
Sorted or unsorted keys
Seek by key or by file offset
IFile is a newer file controller than TFile. It also uses TFile internally so it provides the same features as TFile.