Welcome
What's New
View new features for Accelerator 2025.1.0.
Accelerator Overview
Discover the available Altair Accelerator guides.
Accelerator Tutorials
Discover Accelerator functionality with interactive tutorials.
Altair Accelerator User Guide
Basic tasks in Accelerator, including submitting jobs, tracking job information, and analyzing and solving common problems.
Altair Accelerator Administrator Guide
Configure and manage the use of Accelerator after it is installed.
- Use Accelerator Help
  Accelerator documentation is available in HTML and PDF format.
- Accelerator Quick Start
  Accelerator has two main commands, nc and ncmgr.
- Command Line Interface
- Quick Reference
- Accelerator Server and System Customization
  - Server Configuration
    vovserver configuration parameter values may be changed in a running vovserver using the CLI, or prior to the starting the server via the policy.tcl file. An administator can configure the parameters in the running vovserver using the vovservermgr command or the vtk_server_config procedure.
  - Tasker Configuration
  - Web Server Configuration
  - Configure the TLS/SSL Protocol
    The internal and nginx webservers support TLS/SSL Protocol communication via "https" - prefixed URLs when configured correctly.
  - Altair Accelerator Configuration
    - Job Submission Policy
      The job submission behavior of Accelerator or Accelerator Plus can be controlled by the file vnc_policy.tcl, which resides in the vovserver configuration directory.
    - nc run Command
      The nc 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 administrator can use the file $VOVDIR/local/vncrun.config.tcl to modify some defaults.
    - nc list Command
      This section describes how the Accelerator administrator can use the file $VOVDIR/local/vnclist.config.tcl to modify some defaults for the nc list command. This file does not exist by default; it must be created when needed.
    - nc wait Command
      This section describes how the Accelerator administrator can use the file $VOVDIR/local/vncwait.config.tcl to modify some defaults for the nc wait command. This file does not exist by default; it must be created when needed.
    - Accelerator GUI
    - Web Interface
  - Configuration Management (CM) Guide
    It is a recommended best practice to employ change control on your project configuration files.
  - Browser-based Setup
    Once the Accelerator vovserver has been started, you can view and manage it using your web browser.
  - Regulate Access to Accelerator
    To regulate access to Accelerator, the security file vnc.swd/security.tcl must be edited. To deploy the changes after editing the file, Accelerator must be reset.
  - Autostart Directory
    With the command vovautostart, on vovserver startup, scripts can be specified to execute automatically.
  - Autostop Directory
    With the command vovautostop, on vovserver shutdown, scripts can be specified to execute automatically.
  - Test Altair Accelerator
    You may wish to run a few simple jobs to confirm that the system is running properly.
  - Server Error Conditions
    VOV and the jobs it runs depend on external resources such as available licenses, RAM, swap, tmp and disk space, which may become exhausted, damaged or otherwise unavailable. When users are subject to disk quotas, writes may fail when the disk is not completely full.
  - Configure a Failover Server Replacement
    If a server crashes suddenly, VOV has the capability to start a replacement server on a pre-selected host. This capability requires that the pre-selected host is configured as a failover server.
  - Accelerator Daemons
  - Access Control List
    An Access Control List (ACL) is a list of permissions that are attached to an object. The list defines who can access the object (an agent) and what actions the agent can perform on the object.
  - Client Limitation and Tuning
    The maximum number of clients - the combination of vovtaskers, user interfaces and proxies, that can be concurrently connected to a vovserver is limited by the number of file descriptors available.
  - Enabling Time Series Data Stream
    Users are now able to leverage existing Kafka systems and compatible reporting tools to monitor VOV projects.
- Start and Stop Accelerator
- Job Management
- Log Files
- Database
  Accelerator stores historical information about jobs in a relational database. As of version 2015.09, the database is fully integrated and managed as part of Accelerator. This section provides an overview of the components that run and manage the database.
- FairShare
- Jobclasses
- Preemption
  Preemption is the process of reserving or revoking resources from other jobs in order to help "important jobs" finish quickly.
- 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.
- Resource Management with RDS
  This is a usage guide for the Resource Data Service (RDS), an alternative service for managing License resources and License-first scheduling in Accelerator.
- Configure Container Integration
- Streaming Data Service
  The Streaming Data Service (SDS) publishes a time series data stream that can be consumed by existing Kafka systems and compatible reporting tools to monitor VOV projects.
- Environment Management
  To ensure the correct and repeatable behavior of the tools, the environment must be controlled. This chapter explains how VOV supports multiple reusable environments.
- Directories and Files
- Alerts and Notifications
- System Tasks
- Upgrade Accelerator
  This section provides instructions to change the software version on which Accelerator runs.
- Storage Aware Scheduling
  This daemon vovfilerd replaces older daemons like vovisilond, vovnetappd and vovregulatord. Also the utility vovfiler_setup is no longer needed. The visualization of the filer information is now done either via the vovfilerd.cgi page or via the utility vovfilerdgui.
- Frequently Asked Questions and Troubleshooting Tips
- Backwards Compatibility and Migrating from Previous Versions
  This chapter provides information about deprecated features that are still supported. This information is provided should you see older commands in use after a software upgrade or migrating to a newer Accelerator.

Altair Accelerator Configuration

Many aspects of Accelerator behavior can be customized.

Caching of nc list results may be configured in the file $VOVDIR/local/vnclist.config.tcl

# Example content of vnclist.config.tcl
# enable 'nc list' local caching
set NCLIST(cache,enable) 1

# Other variables used in global array NCLIST (not settable)
#set NCLIST(cache,timeout,default)
#set NCLIST(cache,cacheFile)
#set NCLIST(cache,cacheFp)

# environment variables that influence 'nc list' caching
# NC_LIST_FORMAT
# NC_LIST_CACHE_DIR  ; # default ~/.vov/vnclist.caches/<project>...
# NC_LIST_CACHE_TIMEOUT