Hi Chen!
>From my understanding, every operation on the Namenode is logged (and flushed)
>to disk / QJM / shared storage. This includes the addBlock operation. So when
>a client requests to write a new block, the metadata is logged by the active
>NN, so even if it crashes later on, the new active NN would still see the
>creation of the block.
HTH
Ravi
On Tuesday, February 10, 2015 9:38 AM, Chen Song <chen.song...@gmail.com>
wrote:
When the active name node crashes, it seems there is always a chance that the
data blocks in flight will be missing.My understanding is that when the active
name node crashes, the metadata of data blocks in transition which exist in
active name node memory is not successfully captured by journal nodes and thus
not available on standby name node when it is promoted to active by zkfc.Is my
understanding correct? Any way to mitigate this problem or race condition?
--
Chen Song
