Taskers

A tasker is a VOV client that provides computing resources, specifically CPU cycles, to the vovserver.

There are two types of taskers:
  • Direct taskers: agents that offer for computation all the resources of the machine on which they are running
  • Indirect taskers: agents that interface between a VOV project and a scheduler such as Accelerator.

A project can have a mix of direct and indirect taskers. Normally, Accelerator and Monitor use only direct taskers, while FlowTracer projects often interface to schedulers using one or more indirect taskers.

The list of taskers connected to a project is described in the file taskers.tcl, and the main utility to start and stop taskers is vovtaskermgr. Additional configuration can be specified with the taskerClass.table file.

Types of vovtasker Binaries

The main tasker client is called vovtasker but there are other variations of it:
  • vovtasker can run jobs for more than one user; the success depends on file permissions.
  • vovtaskerroot has the ability of switching user identity.
    Note: Accelerator is the only Altair Accelerator product that needs vovtaskerroot.
  • vovtasker.exe has the ability of impersonating users on Windows, subject to a set of rules explained in VOV Windows Impersonation.
  • vovagent is a temporary vovtasker that terminates upon a set of timeouts, and is used mostly in conjunction with LSF or SGE.
  • ftlm_agent is a "thin-client" version of a vovtasker and can be used by Monitor to start and stop license daemons on remote machines.

vovtasker States

The vovtaskers will change states based on workload and operating environment. Generally, the tasker state will accompany the tasker name when displayed in the various user interfaces (CLI, GUI, WUI). The possible states are as follows:
  • BLACKHOLE: temporarily paused due to a burst of job failures and cannot accept jobs
  • BUSY: busy with internal operations
  • DEAD: has disconnected and cannot accept jobs
  • DONE: exiting after completing current jobs
  • FULL: full and cannot accept more jobs
  • OVRLD: overloaded and cannot accept jobs
  • NOLIC: unlicensed and cannot accept jobs
  • NOSLOT: configured to not accept job
  • OK: idle and ready for jobs
  • PAUSED: paused and cannot accept jobs
  • READY: idle and ready for jobs
  • REQUESTED: has been requested to start
  • SICK: sick and possibly disconnected
  • SUSP: suspended and cannot accept jobs
  • WARN: in a warning state and should be checked
  • WRKNG: working and can accept more job