== [[PoolPage]] PoolPage -- Fair Scheduler Pool Details Page

[[prefix]] PoolPage is a spark-webui-WebUIPage.md[WebUIPage] with pool spark-webui-WebUIPage.md#prefix[prefix].

The Fair Scheduler Pool Details page shows information about a spark-scheduler-Pool.md[Schedulable pool] and is only available when a Spark application uses the spark-scheduler-SchedulingMode.md#FAIR[FAIR scheduling mode] (which is controlled by configuration-properties.md#spark.scheduler.mode[spark.scheduler.mode] configuration property).

.Details Page for production Pool image::spark-webui-pool-details.png[align="center"]

PoolPage renders a page under /pool URL and requires one request parameter <> that is the name of the pool to display, e.g. http://localhost:4040/stages/pool/?poolname=production. It is made up of two tables: <> (with the details of the pool) and <> (with the active stages in the pool).

PoolPage is <> exclusively when StagesTab is spark-webui-StagesTab.md#creating-instance[created].

[[creating-instance]] [[parent]] PoolPage takes a spark-webui-StagesTab.md[StagesTab] when created.

PoolPage uses the parent's SparkContext.md#getPoolForName[SparkContext to access information about the pool] and spark-webui-JobProgressListener.md#poolToActiveStages[JobProgressListener for active stages in the pool] (sorted by submissionTime in descending order by default).

=== [[PoolTable]][[pool-summary]] Summary Table

The Summary table shows the details of a spark-scheduler-Schedulable.md[Schedulable pool].

.Summary for production Pool image::spark-webui-pool-summary.png[align="center"]

It uses the following columns:

  • Pool Name
  • Minimum Share
  • Pool Weight
  • Active Stages - the number of the active stages in a Schedulable pool.
  • Running Tasks
  • SchedulingMode

All the columns are the attributes of a Schedulable but the number of active stages which is calculated using the spark-webui-JobProgressListener.md#poolToActiveStages[list of active stages of a pool] (from the parent's spark-webui-JobProgressListener.md[JobProgressListener]).

=== [[StageTableBase]][[active-stages]] Active Stages Table

The Active Stages table shows the active stages in a pool.

.Active Stages for production Pool image::spark-webui-active-stages.png[align="center"]

It uses the following columns:

  • Stage Id
  • (optional) Pool Name - only available when in FAIR scheduling mode.
  • Description
  • Submitted
  • Duration
  • Tasks: Succeeded/Total
  • Input -- Bytes and records read from Hadoop or from Spark storage.
  • Output -- Bytes and records written to Hadoop.
  • Shuffle Read -- Total shuffle bytes and records read (includes both data read locally and data read from remote executors).
  • Shuffle Write -- Bytes and records written to disk in order to be read by a shuffle in a future stage.

The table uses spark-webui-JobProgressListener.md#stageIdToData[JobProgressListener for information per stage in the pool].

=== [[parameters]] Request Parameters

==== [[poolname]] poolname

poolname is the name of the scheduler pool to display on the page. It is a mandatory request parameter.

Last update: 2020-11-27