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We found a way to implement our nodescheduler script in Slurm using the --exclude option.  Is there a way to exclude certain hosts from a job?  Or perhaps a constraint that prevents a job from running on a node that is already running a job of that user?

CPU Shares

Torque uses cpusets which is pretty straight forward, but cpu.shares confuses me a bit.

condor_ssh_to_job

  Is there a better way than this?

requirements = Machine != "nmpost097.aoc.nrao.edu" && Machine != "nmpost119.aoc.nrao.edu"

Memory usage report

The memory usage report at the end of the condor log seems incorrect.  I can watch the memory.max_usage_in_bytes in the cgroup get over 8,400MB yet the report in the condor log reads 6,464MB.  Does the log only report the memory usage of the parent process and not include all the children?  Is it an average memory usage over time?


condor_ssh_to_job

Is there a way to use condor_ssh_to_job to connect to a Is there a way to use condor_ssh_to_job to connect to a job submitted from a different submit host (schedd) or do you have to run it from the submit host used to submit the job?  I have tried using the -name option to condor_ssh_to_job but I always get Failed to send GET_JOB_CONNECT_INFO to schedd

Memory usage report


CPU Shares

Torque uses cpusets which is pretty straight forward, but HTCondor uses cpu.shares which confuses me a bit.  For example, a job with request_cpus = 8 executing on a 24-core machine gets cpu.shares = 800  If there are no other jobs on node, does this job essentially get more CPU time than 1024/800The memory usage report at the end of the condor log seems incorrect.  I can watch the memory.max_usage_in_bytes in the cgroup get over 8,400MB yet the report in the condor log reads 6,464MB.  Does the log only report the memory usage of the parent process and not include all the children?



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Answered Questions:

  • JOB ID question from Daniel

    • When I submit a job, I get a job ID back. My plan is to hold onto that job ID permanently for tracking. We have had issues in the past with Torque/Maui because the job IDs got recycled later and our internal bookkeeping got mixed up. So my questions are:

       - Are job IDs guaranteed to be unique in HTCondor?
       - How unique are they—are they _globally_ unique or just unique within a particular namespace (such as our cluster or the submit node)?

    • A Job ID (ClusterID.ProcID)
    • DNS name of the schedd and ctime of the job_queued.log file.
    • It is unique to a schedd.
    • We should talk with Daniel about this.  They should craft their own ID.  It could be seeded with a JobID but should not depend on just it.
  • UpgradingHTCondor without killing jobs?
    • schedd can be upgraded and restarted without loosing state assuming the restart is less than the timeout.
    • currently restarting execute services will kill jobs.  CHTC is working on improving this.
    • negotiator and collector can be restarted without killing jobs.
    • CHTC works hard to ensure 8.8.x is compatible with 8.8.y or 8.9.x is compatible with 8.9.y.
  • Leaving data on execution host between jobs (data reuse)
    • Todd is working on this now.
  • Ask about installation of CASA locally and ancillary data (cfcache)
    • CHTC has a Ceph filesystem that is available to many of their execution hosts (notibly the larger ones)
    • There is another software filesystem where CASA could live that is more used for admin usage but might be available to us.
    • We could download the tarball each time over HTTP.  CHTC uses a proxy server so it would often be cached.
  • Environment:  Is there a way to have condor "login" when a job starts thus sourcing /etc/proflie and the user's rc files? Currently, not even $HOME is set.
    • A good analogy is Torque does a su - _username_ while HTCondor just does a su _username_
    • WORKAROUND: setting getenv = True which is like the -V option to qsub, may help. It doesn't source rc files but does inherit your current environment. This may be a problem if your current environment is not what you want on the cluster node. Perhaps the cluster node is a different OS or architecture.
    • ANSWER: condor doesn't execute things with a shell.  You could set your executable as /bin/bash and then have the arguments be the executable you used to have.  I just changed our stuff to staticly set $HOME and I think that is good enough.

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