admin:overview:why_a_computing_grid_in_a_desktop_office_environment [Promethee]

Why a computing grid in a desktop office environment ?

Even if a Windows desktop network is not a dedicated environment to provide significant computing power, many operational entities may benefit to deploy a grid on their desktop computers:
  • total cost ownership (TCO) of servers fleet is too hight to be covered by numerical engineering gains,
  • high constraints of server fleet operation
    • reduced disk space or lack of computing power,
    • computer codes portability,
    • inadequate network architecture (latency or communication tools),
    • administration lack of flexibility (outsourcing),
  • need for punctual autonomy from server fleet:
    • network instability or unavailability,
    • office laptop disconnection.

At the same time, raw computing power of a grid is nowadays close to office network one:
  • raising of unit power and decreasing of load average,
  • multiplication of CPU/core inside each computer,
  • high and continuous hardware turnover.

However if this potential power can theoretically compete with a fleet of servers, the constraints for using an office network as a grid are:
  • Desktop ergonomic impact: when a calculation is started, the user of the machine hosting the calculation should not be penalized in his office use,
  • Portability of computer codes on Windows: most computer codes are compiled only for Linux or Unix architectures, Windows porting is not available,
  • Hardware heterogeneity of office desktops: need for dynamic and efficient load balancing,
  • Instability of configuration: disconnection and dynamic unplug of desktop or laptops.

PWinG : Promethee Windows Grid

The PWinG subproject is designed to solve the previous technical issues in order to build a computing grid from an office desktop environment.
Office desktop usage is then seamlessly integrated inside the computing power offered by the traditional dedicated servers calculations (if available).

In common use, the Promethee environment is installed as a daemon on servers dedicated to calculation and provides a graphical interface on the workstations of users.
In a PWinG grid, in addition to the graphical user interface, the daemon is also running on desktop computers to integrate their power into the grid. In such a case, the Promethee grid may include only desktop computers or merge both office desktop and servers.
The previous constraints and issues are solved as follows:
  • Desktop ergonomy impact:
    • day-parting control of Promethee calculation service,
    • selection of authorized computing tasks,
    • definition of number of CPU used,
  • Portability of computer codes on Windows: ideally, computing software may be available on Windows platform.
    However, this portage on Windows x86 architecture is not possible for many codes, for technical reasons (sources are not portable) or commercial (source code not available). As part of the project, a virtualization solution is used to allow execution of code compiled for Linux on x86 Windows: a coLinux virtual machine is packaged to execute the Promethee daemon installed in the directory of the Windows host machine.
  • Management of computing fleet: heterogeneity and dynamic load balancing are handled by Promethee grid, designed to support such constraints.
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