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Accelerator Plus Administrator Guide
This guide is written for the Accelerator Plus system administrator who needs to configure and manage one or more Accelerator Plus instances.
Accelerator Plus Server and System Configuration
Using Direct Drive with vovwxd
Direct Drive provides a method to reduce latency of job start times and improved scaling as more base queues are added.

Welcome
What's New
View new features for Accelerator Plus 2025.1.2.
Accelerator Plus Overview
Accelerator Plus is a high-performance hierarchical scheduler designed for distributed High Performance Computing (HPC) environments.
Accelerator Plus Tutorials
Currently there are no Accelerator Plus tutorials available.
Accelerator Plus User Guide
Accelerator Plus is a high-performance hierarchical scheduler designed for distributed High Performance Computing (HPC) environments.
Accelerator Plus Administrator Guide
This guide is written for the Accelerator Plus system administrator who needs to configure and manage one or more Accelerator Plus instances.
- System Overview
  Accelerator Plus is a high-performance hierarchical scheduler designed for distributed High Performance Computing (HPC) environments.
- Accelerator Plus Server and System Configuration
  - Start and Stop Accelerator Plus
    The command wxmgr is identical to ncmgr.
  - Integration with PBS
    Accelerator Plus has added the capability to use PBS Professional as its base scheduler. For the 2019.01 release, jobs can be submitted through Accelerator Plus and run on a PBS complex.
  - Daemons for Accelerator Plus
    Some key functionality in Accelerator Plus is provided by external daemons.
  - Theory of Operation
    This section describes the theory of the operation of Accelerator Plus on Accelerator and how to address problems should they occur.
  - vovwxd Configuration
    In order to successfully run jobs under Accelerator Plus, submitting to Accelerator, some configuration must be done up front.
  - Using Direct Drive with vovwxd
    Direct Drive provides a method to reduce latency of job start times and improved scaling as more base queues are added.
  - VOV Security Keys
  - Regulate Access to Accelerator Plus
    Like all vovservers, access to Accelerator Plus can be controlled by editing the security file wx.swd/security.tcl.
  - Job Status
    In Accelerator Plus, each job goes through a number of states until completion.
  - Job Submission Policy
    The job submission behavior of Accelerator Plus or Accelerator Plus can be controlled by the file vnc_policy.tcl, which resides in the vovserver configuration directory.
  - Accelerator Plus Customization
    Many aspects of Accelerator Plus behavior can be customized.
  - Customize the wx run Command
    The wx run command has built-in default features that include checking the validity of the run directory, enabling job profiling, etc. This section describes how the Accelerator Plus administrator can use the file $VOVDIR/local/vncrun.config.tcl to modify some defaults. This file does not exist by default; it must be created when needed.
  - Customize the wx list Command
    This section describes how the Accelerator Plus administrator can use the file $VOVDIR/local/vnclist.config.tcl to modify some defaults for the wx list command. This file does not exist by default; it must be created when needed.
  - Troubleshooting
  - Job Placement Policies
  - Web Server Configuration
  - Web Interface
    Some features of the Accelerator Plus web interface can be configured by the administrator. Configuration for these items is performed in the vnc.swd/config/web.cfg file.
  - Using Accelerator as a Base Scheduler
    When interfacing to Accelerator, a minimal (zero) configuration for Accelerator Plus is recommended.
  - Many Accelerator Plus Queues on Many Accelerator Queues
- Log Files
- Jobclasses
- Resource Management
  Altair Accelerator includes a subsystem for managing computing resources. This allows the design team to factor in various constraints regarding hardware and software resources, as well as site policy constraints.
- Frequently Asked Questions and Troubleshooting Tips
  This section provides recommendations to obtain the maximum performance from Accelerator Plus.

View All Altair Accelerator Help

Using Direct Drive with vovwxd

Direct Drive provides a method to reduce latency of job start times and improved scaling as more base queues are added.

Accelerator Plus and FlowTracer utilize a Direct Drive mechanism in vovwxd to bypass the driver script and speed up tasker requests into the base queue. The WXLauncher tasker is no longer required and the use of launcher jobs is avoided. The call backs defined in the vovnc.tcl script are no longer active, although a future version may reinstate some of them.

Note: Direct Drive only works using an NC base queue 2021.1.1 or higher.

Set up a WX queue with one or more base NC queues.
Copy the vovaccel.tcl file to the SWD/vovwxd directory.

In the vovwxd config.tcl file, set the following parameters:

set CONFIG(plugin)			"libvovaccel.so"
set CONFIG(driver_script)     "vovaccel.tcl"

When a request is issued, vovwxd will create a copy of the local bucket in the base queue. This bucket will appear as "foreign bucket" in the base queue. Bucket objects now have new fields to accommodate the foreign buckets: isforeign, wxbucketid, and wxqueue. These can be queried with vovselect.

Note: DirectDrive uses a different format of a driver script. The CONFIG(driver_script) parameter must specify an appropriate script. An example is available in $VOVDIR/etc/config/vovwxd/vovaccel.tcl.

set CONFIG(driver_script) "vovaccel.tcl"

Currently only two procedures are supported: OnProcessBucket BUCKETINFO (for filtering buckets) and OnConfigLoaded(CONFIG), which is called when the config file is modified.