TaskDescription — Metadata of Single Task-spark技术分享

TaskDescription — Metadata of Single Task

TaskDescription is a metadata of a single task with the following properties:

The name of the task is of the format:



task [taskID] in stage [taskSetID]

task [taskID] in stage [taskSetID]

TaskDescription is created when:

TaskSetManager is requested to find a task ready for execution (given a resource offer)
TaskDescription is requested to decode (a TaskDescription from a serialized format as a ByteBuffer)

The textual representation of a TaskDescription is as follows:



TaskDescription(TID=[taskId], index=[index])

TaskDescription(TID=[taskId], index=[index])



decode(byteBuffer: ByteBuffer): TaskDescription

decode(byteBuffer: ByteBuffer): TaskDescription

decode…FIXME

Note	`decode` is used when: `CoarseGrainedExecutorBackend` is requested to handle a LaunchTask message Spark on Mesos’ `MesosExecutorBackend` is requested to launch a task



encode(taskDescription: TaskDescription): ByteBuffer

encode(taskDescription: TaskDescription): ByteBuffer

encode…FIXME

Note	`encode` is used when: `DriverEndpoint` (of `CoarseGrainedSchedulerBackend`) is requested to launchTasks Spark on Mesos’ `MesosFineGrainedSchedulerBackend` is requested to `createMesosTask`