spark-core-LiveEntity.adoc

LiveEntity

LiveEntity is the contract of a live entity in Spark that…​FIXME

package org.apache.spark.status

abstract class LiveEntity {
  // only required methods that have no implementation
  // the others follow
  protected def doUpdate(): Any
}

Note	LiveEntity is a private[spark] contract.

Table 1. LiveEntity Contract

Method	Description
doUpdate	Used exclusivey when LiveEntity is requested to write.

LiveEntity tracks the last write time (in lastWriteTime internal registry).

write Method

write(store: ElementTrackingStore, now: Long, checkTriggers: Boolean = false): Unit

write requests the input ElementTrackingStore to write the updated value.

In the end, write records the time in the lastWriteTime.

Note	write is used when: AppStatusListener is requested to update SQLAppStatusListener is created (and registers a flush trigger) and requested to update