I read the QJM in hadoop official documentation but there is no clear control flow explanation
So far I understand was
When the namenode fails zookeeper failure controller will detect and change the standby namenode as active namenode.
Only active namenode will write the edit log in Journal node
- Journal will sync the edit log with standby namenode
Can any one please explain how the real flow works?
- step 1: when client connects request goes here ....
- step 2: it will take care of these request ....
- step 3: if it fails it will happen the request will go there....
Like that can anyone please explain the complete flow of QJM
Thanks in advance