Database Reference
In-Depth Information
Figure 16.12
NameNode summary
The MapReduce Service Summary shows summary trends of jobs,
TaskTrackers, slots utilization, and total number of maps compared to total
number of reducers. The Jobs Summary report details jobs submitted, jobs
failed, jobs completed, and jobs killed. The TaskTrackers Summary report
provides information on TaskTrackers decommissioned, TaskTrackers
blacklisted,TaskTrackersgraylisted,andnumberofTaskTrackers. TheSlots
Utilization graph shows reserved and occupied reduce slots and reserved
and occupied map slots. Finally, the Maps vs. Reducers reports details the
number of running map and reduce tasks over time. You will likely visit this
summary page often when users are complaining about slow performance,
asitwillgiveyouquickinsighttotheaggregateactivityonthecluster.
Figure
16.13
shows the MapReduce Summary report.
