Database Reference
In-Depth Information
•
Counter information
: Hadoop has several built-in counters that provide informa-
tion about the job being executed. These counters help us understand the behavior
of the job and also assist us identify problems with a job a job. Developers can
also build custom counters to track certain aspects of their application. The
counter information section provides filesystem counter information, job counter
information, and statistics related to the MapReduce operations of the job.
The following screenshot shows the counter information section:
•
Map and reduce completion graphs
: The map and reduce completion graphs
provide a graphical representation of the map and reduce tasks for the job. The
map completion graph shows progress information of all the map tasks submitted
