Apache Ambari Views
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Using Counters to Identify the Cause of Slow-Performing Jobs

Tez View shows counters so you can understand why a task performs more slowly than expected. Counters help you better understand the task size and enable you to locate anomalies. Elapsed time is one of the primary counters to look for.

Counters are available at the DAG, vertex, and task levels. As of Tez View in Ambari 2.5.0, the following Hive LLAP counter information is displayed:

Group: org.apache.hadoop.hive.llap.counters.LlapIOCounters
Counters: CACHE_HIT_BYTES, CACHE_MISS_BYTES, METADATA_CACHE_HIT, METADATA_CACHE_MISS

Figure 11.12. Tez View DAG-Level Counters Tab


As of Tez View in Ambari 2.5.0, the Vertex Swimlane tab is also available. The information here is about vertex processor details for Hive and Pig.

Figure 11.13. Tez View Vertex Swimlane Tab


If you want to view the information about the vertex processing in a different format, open a vertex to see the Vertex Details sutab. A Description pane at the bottom of the window is from the user payload of the respective vertex in the DAG plan.

Figure 11.14. Tez View Vertex Details Subtab


Figure 11.15. Tez View Vertex-Level Counters Tab


Figure 11.16. Tez View Task-Level Counters Tab


Monitoring Task Progress for Jobs

The Tez View shows task progress by increasing the count of completed tasks and total tasks. This enables you to identify the tasks that might be "hung" and to understand more about long-running tasks.