NN HA : will edit log writes to journal nodes impacts the NN's perforrmace ?

[kumar y <yk...@gmail.com>]

I have gone through the QJM design doc but i still want to make sure this
particular point.

In NN HA setup with QJM, i understood the journal manager class in namenode
takes care of writing edit logs to all journal nodes and i am guessing that
this does not impact the NN's performance because NN still continue to
write its own edit logs to its local disk with out waiting for Journal node
confirmation, is this right ? or does NN actually wait for the edit log
transactions to be written to all journal nodes ?