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- What limits are there to transfer_input_files? I would sometimes get Failed to transfer files when the number of files was around 10,000
- ANSWER: There is a memory limit because of ClassAds but in general there isn't a defined limit.
- Is there a way to generate the dag.dot file without having to submit the job?
- The -no_submit option doesn't create the .dot file
- Is adding NOOP to all the JOB commands the right thing to do? The DAG still gets submitted but then quickly ends.
- ANSWER: You need to submit the DAG. NOOP is the current solution
- Is there a way to start a dag at a given point? E.g. if there are 5 steps in the dag, can you start the job at step 3?
- Is the answer again to add NOOP to the JOB commands you don't want to run?
- ANSWER: Splices may work here.
- I see at CHTC jobs now require a request_disk setting. How does one launch interactive jobs?
- ANSWER: This is a bug.
- For our initial tests, we want to flock jobs to CHTC that transfer about 60GB input and output. Eventually we will reduce this significantly but for now what can we do?
- Globus or rsync to move data? If Globus, how to do so in an automated way (E.g. no password)?
- ANSWER: Using the Transfer Mechanism from our submit server to CHTC's execution host is ok with CHTC because it doesn't interfere with their submit host. Outbound from their execute hosts is also allowed (scp, rsync, etc).
- Use +Longjob = true attribute for 24+ hour jobs. This is a CHTC-specific knob.
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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