The Tasks tab contains a list of the Map and Reduce task attempts that make up a job.
Viewing a Job's Task Attempts
- From the Clusters tab, in the section marked Other, select the activity you want to inspect.
- If the activity is a MapReduce job, the Tasks tab opens.
- If the activity is a Pig, Hive, or Oozie activity, select the job you want to inspect from the activity's Children tab to open the Tasks tab.
The columns shown under the Tasks tab display statistics about the performance of and resources used by the task attempts spawned by the selected job. By default only a subset of the possible metrics are displayed — you can modify the columns that are displayed to add or remove the columns in the display.
- The status of an attempt is shown in the Attempt Status column:
The attempt is running.
The attempt has succeeded.
The attempt has failed.
The attempt has been unassigned.
The attempt has been killed.
The attempt's final state is unknown.
- Click the task ID to view details of the individual task.
You can use the Zoom to Duration button to zoom the Time Range Selector to the exact time range spanned by the activity whose tasks you are viewing.
Selecting Columns to Show in the Tasks List
- Click the Select Columns to Display icon (). A pop-up panel lets you turn on or off a variety of metrics that may be of interest.
- Check or uncheck the columns you want to include or remove from the display. As you check or uncheck an item, its column immediately appears or disappears from the display.
- Click the in the upper right corner to close the panel.
Sorting the Tasks List
- Click the column header to initiate a sort. The small arrow that appears next to the column header indicates the sort direction.
- Click the column header to reverse the sort direction.
Filtering the Tasks List
You can filter the list of tasks based on values of any of the metrics that are available.
- Click the to the right of the Search button and select the filter you want to run. There are predefined filters to search by job type (for example Pig activities, MapReduce jobs, and so on) or for running, failed, or long-running activities.
- Click the to the right of the Search button and select Custom.
- Select a metric from the drop-down list in the first field; you can create a filter based on any of the available metrics.
- Once you select a metric, fill in the rest of the fields; your choices depend on the type of metric you have selected. Use the percent character % as a wildcard in a string; for example, Id matches job%0001 will look for any MapReduce job ID with suffix 0001.
- To create a compound filter, click the plus icon at the end of the filter row to add another row. If you combine filter criteria, all criteria must be true for an activity to match.
- To remove a filter criteria from a compound filter, click the minus icon at the end of the filter row. Removing the last row removes the filter.
- To include any children of a Pig, Hive, or Oozie activity in your search results, check the Include Child Activities checkbox. Otherwise, only the top-level activity will be included, even if one or more child activities matched the filter criteria.
- Click the Search button (which appears when you start creating the filter) to run the filter.