10.2.7. The generic Tags mechanism for jobs matching

DIRAC provides a generic mechanism for matching computing capabilities with resource providers, and this is done using generic “Tags”. Tags can be used by the users to “mark (tag)” their jobs with requirements, and should be used by DIRAC admins to identify CEs or Queues.

So, as always it’s a matter of what’s written in the CS:

• Meaning that a CE or a Queue has Tag=X means that it’s capable() of running jobs that *require Tag=X.

• Meaning that a CE or a Queue has RequiredTag=X means that it will accept only jobs that require Tag=X.

Let’s take an example:

DIRAC.MySite.org
{
  Name = Test
  CEs
  {
    CE.MySite.org
    {
      CEType = Test
      Queues
      {
        # This queue exposes no Tags. So it will accept (match) all jobs that require no tags
        noTagsQueue
        {
          # the following fields are not important
          SI00 = 2400
          maxCPUTime = 200
          MaxTotalJobs = 5
          MaxWaitingJobs = 10
          RemoveOutput = True
        }
        # This queue has Tag = GPU. So it will accept:
        # - jobs that require Tag = GPU (and no others)
        # - jobs that require no Tags
        GPUTagQueue
        {
          Tag = GPU
          ...
        }
        # This queue has Tag = [GPU, NVidiaGPU]. So it will accept:
        # - jobs that require both the tags above (and no others)
        # - jobs that require Tag = GPU (and no others)
        # - jobs that require Tag = NVidiaGPU (and no others)
        # - jobs that require no Tags
        MultipleGPUTagQueue
        {
          Tag = GPU
          Tag += NVidiaGPU
          ...
        }
        # This queue has Tag = GPU and RequiredTag = GPU. So it will accept:
        # - jobs that require Tag = GPUs (and no others)
        RequiredGPUTagQueue
        {
          Tag = GPU
          RequiredTag = GPU
          ...
        }
        # This queue has Tag = [GPU, NVidiaGPU] and RequiredTag = GPU. So it will accept:
        # - jobs that require both the tags above (and no others)
        # - jobs that require Tag = GPU (and no others)
        MultipleGPUTagQueue
        {
          Tag = GPU
          Tag += NVidiaGPU
          RequiredTag = GPU
          ...
        }
      }
    }
    # Tags can also be given to CEs. So, the following CE accepts ALSO GPU jobs.
    # The same examples above, which were done for the queues, apply also to CEs
    GPU-CE.cern.ch
    {
      Tag = GPU
      Queues
      {
        some_queue
        {
           ...
        }
      }
    }
  }
}