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
    - Taskers
      A tasker is a VOV client that provides computing resources, specifically CPU cycles, to the vovserver.
    - Create a Tasker on Windows
    - UNIX User Impersonation
      A normal vovtasker has the privileges and limitations of the account in which it runs. When a normal vovtasker executes a command, the effect is the same as when the vovtasker's owner runs the command.
    - The taskers.tcl File
      The taskers.tcl file describes the taskers for a project.
    - vtk_tasker_define
      There are many options that can be used with vtk_tasker_define and vtk_tasker_set_default.
    - Tasker Attributes
      A tasker is characterized by several attributes. These attributes are controllable by means of the command line arguments to the vovtasker binary as well as by means of the procedure vtk_tasker_define in the taskers.tcl configuration file for a VOV project.
    - Manage Tasker Lists
      A tasker list is a named, ordered list of taskers. Tasker lists can be used to enhance performance or restrict usage.
    - Control the Capacity of Taskers: Slots and Cores
      The resources of a tasker include SLOTS, SLOTSTOTAL, CORES and CORESTOTAL.
    - Tasker Health Checks
      By default, the vovtasker does not perform many health checks. If the jobs can be executed successfully, that is normally enough of a check.
    - Configuration File for vovagent
      For cases where the vovtaskers are started by submitting the binary to a separate batch queue system such as LSF or SGE, the system administrator may decide to use vovagent, which is a special copy of the vovtasker binary.
    - Tasker Load Reports
      vovtasker continuously logs 1 minute, 5 minute and 10 minute load averages of the machine where the tasker is running. Tasker load reports are available on the Tasker Load page.
    - RAM Sentry
    - Define Policies for Taskers
    - Time-Variant Taskers
      Time-variant taskers resources can be configured using Tcl. Any procedure can be defined in the namespace VovResources and then used to compute the resource list.
    - Allocate Jobs to Machines Based on Percentages
    - SGE Style Load Sensors
      vovtaskers also support SGE style load sensors. Use option -L in vovtasker/vovtaskerroot to define the command line for the load sensor.
    - Start a Remote UNIX Tasker
    - Taskers on Windows
    - Windows User Impersonation
    - Manage Remote Taskers without SSH/RSH Capabilities
    - Black Hole Detection
    - Troubleshooting a SICK Tasker
    - Tasker Reservations
    - Clean up Processes Left Behind by Completed Jobs
  - 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
  - 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.

View All Altair Accelerator Help

RAM Sentry

The RAM Sentry mechanism monitors the RAM utilization of the jobs and performs safety measures to prevent the tasker's memory resources from becoming saturated.

The RAM Sentry currently has one level of protection:

Suspend at swap: For taskers that have multiple jobs running, if the tasker enters swap, the RAM Sentry suspends all jobs other than the job with the largest RAM footprint. When the large job completes, the smaller jobs will resume. While the RAM Sentry is active, the tasker itself is also suspended, preventing any new jobs from being accepted.

Enable RAM Sentry

To enable the RAM Sentry, set the variable VOV_RAM_SENTRY to 1 before starting a tasker. A simple choice is to add the following line to the $VOVDIR/../../vnc/vnc.swd/setup.tcl file, so that all taskers have this functionality enabled:

# Add this to the vnc.swd/setup.tcl file.
setenv VOV_RAM_SENTRY 1

After the tasker has started, you can control the mechanism for each individual tasker with vovtaskermgr configure -ramsentry <boolean> ..., as in the following examples:

% vovtaskermgr configure -ramsentry 1 linux010
% vovtaskermgr configure -ramsentry 0 linux010