In createDirectory and createFile, journaling happens only when the creation succeeds, so if only a part of the paths are created/persisted successfully, the changed states will not be journaled, and inconsistency will occur after restarting the master.
What's your thought on this?
Alluxio journaling only addresses Alluxio metadata consistency. There are no guarantees about consistency between the Alluxio and the UFS; if the master is killed mid-operation between UFS modification and journal write, Alluxio<->UFS inconsistency is possible. To address this, we would need to implement a transaction/rollback mechanism.