- from horton works
- scanner.cursor
-
File to which the "cursor state" is saved.
The DataNode runs a block scanner which periodically does checksum verification of each block file on disk. This scanner maintains a "cursor," representing the last block to be scanned in each block pool slice on the volume, and called the "cursor state."
from cloudera
To keep track of the scanning position among the blocks, a block cursor is maintained for each volume. The cursor is saved to disk periodically (interval is configurable via dfs.block.scanner.cursor.save.interval.ms, the default value is 10 minutes). This way, even if the DataNode process restarts or the server reboots, the scan doesn’t have to restart from the very beginning.
vi scanner.cursor
{
"lastSavedMs" : 1524041646447,
"iterStartMs" : 1524041646444,
"curFinalizedDir" : null,
"curFinalizedSubDir" : null,
"curEntry" : null,
"atEnd" : true
}
what these values related to the definition?
and also dfs.block.scanner.cursor.save.interval.ms property is not available hadoop docs
