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Altair Accelerator Administrator Guide
Configure and manage the use of Accelerator after it is installed.
Preemption
Preemption is the process of reserving or revoking resources from other jobs in order to help "important jobs" finish quickly.
Control Whether a Job is Preemptable

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
- 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.
  - Set Up the Optional Preemption Ruler Compiler Daemon
  - Preemption Rules
  - Preemption Examples
  - Preemption Methods
  - Preemption Plans
    Preemption plans are the building blocks of preemption methods and allow the implementation of custom, complex multi-step preemption sequences.
  - Web-Based Interface for Preemption
    The Accelerator web interface provides a form-based method of entering preemption rules and methods, and viewing statistics regarding the activation of previously entered preemption rules.
  - Preemption Rules to Speed Up FairShare
  - Preemption Over Altair Allocator
  - Preempt Jobs with Unrequested Resources
  - Control Whether a Job is Preemptable
  - Preemption Timing
    The preemption subsystem has a complex behavior, controlled by many delays that are described in this section.
  - Start the Preemption Rule Compiler Daemon vovpreemptd
  - Manual Preemption
    Manual preemption can be used in addition to or instead of automatic preemption.
  - Preempting Tokens
  - Remove Licenses from a Preempted Job
- 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.

Control Whether a Job is Preemptable

This field is a boolean and identifies the jobs that can be preempted.

This flag can be set using the variable make(preemptable) in a FDL file.

In Accelerator, all jobs are preemptable by default. To disable the flag, use the option -preemptable 0 at submission time.

% nc run -preemptable 0 sleep 100

Note: See @KEYWORD* Expansion for details on using @KEYWORD@ expansion with -preemptable.