Does Windows Azure Scheduler split a job into several parallel jobs on one Compute node?

Question

Windows Azure HPC Scheduler assigns tasks in local queues of Compute Nodes. But is it possible that different tasks will run in parallel on one node? Is it possible that a potentially parallel task will be divided into sub tasks to run simultaneously on Compute Node?

Answer 1

HPC Scheduler has only one queue. So all Jobs run independently if there are enough resources, e.g. enough CPU cores. One Job can have many tasks.

How they run it depends on a type of task. Here are all the task types:

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. This task type is the default. This enumeration member represents a value of 0.

NodePrep
Runs a command or script on each compute node as it is allocated to the job. The Node Prep task runs on a node before any other task in the job. If the Node Prep task fails to run on a node, then that node is not added to the job. This enumeration member represents a value of 2.

NodeRelease
Runs a command or script on compute each node as it is released from the job. Node Release tasks run when the job is canceled by the user or by graceful preemption. Node Release tasks do not run when the job is canceled by immediate preemption. This enumeration member represents a value of 3.

ParametricSweep
Runs a command a specified number of times as indicated by the 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 HPC cluster when the task is running. This enumeration member represents a value of 1. Service Runs a command or service on all resources that are assigned to the job. New instances of the command are started when new resources are added to the job, or if a previously running instance exits and the resource that the previously running instance was running on is still allocated to the job. A service task continues to start new instances until the task is canceled, the maximum run time expires, or the maximum number of instances is reached. A service task can create up to 1,000,000 sub-tasks. Tasks that you submit through a Service Oriented Architecture (SOA) client run as service tasks. You cannot add a basic task or a parametric sweep task to a job that contains a service task. This enumeration member represents a value of 4.

You can read about different types here:
http://technet.microsoft.com/en-us/library/ee783566(v=ws.10).aspx