[This topic is pre-release documentation and is subject to change in future releases. Blank topics are included as placeholders.]

In Windows HPC Server 2008 R2, the Type task property helps define how to run a command. Task types can have the following values:

The default task type value is Basic. You can use the Type property to denote a Parametric Sweep, Node Preparation, Node Release, or Service task.

The following table describes the property values:

Task Type Value Description

Basic

Runs a single instance of a serial application or a Message Passing Interface (MPI) application. An MPI application typically runs concurrently on multiple cores and can span multiple nodes.

Parametric Sweep

Runs a command a specified number of times (indicated by start, end, and increment values), generally across indexed input and output files. The steps of the sweep may or may not run in parallel, depending on the resources that are available on the cluster when the task is running.

In HPC PowerShell™, Parametric Sweep replaces the –Parametric task property.

Node Preparation

Runs a command or script on each node as it is allocated to the job. The Node Preparation task runs on a node before any other task in the job.

If the Node Preparation task fails to run on a node, then that node is not added to the job.

Node Release

Runs a command or script on each node as it is released from the job.

The default maximum run time (in seconds) for Node Release tasks is set with the NodeReleaseTaskTimeout cluster parameter. To see the cluster parameter values, open a command prompt window and type cluscfg listparams.

Note

If a job has a maximum run time and a Node Release task, the scheduler cancels the other tasks in the job before the run time of the job expires (job run time minus Node Release task run time). This allows the Node Release task to run within the allocated time for the job.

Service

Runs a command or service on all resources that are allocated to the job. New instances of the command start when new resources are added to the job or if a previously running instance exits and the resource that it was running on is still allocated to the job. Service tasks continue to start instances until the job is canceled or stopped, the maximum run time expires, or until the maximum number of instances is reached (a Service task can create up to 1,000,000 subtasks).

Tasks that are submitted through a service-oriented architecture (SOA) client run as Service tasks.

Note

You cannot add a Basic task or a Parametric Sweep task to a job that contains a Service task.

The following task properties do not apply to tasks that are started on a per-resource basis, and they cannot be set on the Node Preparation, Node Release, or Service tasks:

  • Scenario: When to Use Node Preparation and Node Release Tasks
  • Steps: Submit a Job with a Node Preparation and a Node Release Task