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CHTC

UW Research Computing

Policies for Using HTC Submit Servers

If you have not yet requested a CHTC account and met with a Research Computing Facilitator, please fill out this form.

Recently created CHTC accounts will use our submit server submit1.chtc.wisc.edu. Accounts created before Feb 1, 2023 may be on either submit1.chtc.wisc.edu or submit2.chtc.wisc.edu. See our connecting guide for additional information.

Access to other submit servers is granted for specific purposes and will have been indicated to you by CHTC staff.

Connecting to HTC Submit Servers

Once your account is active, you can connect to your designated submit server with an SSH connection ("Putty" for Windows, putty.org; "Terminal" for Linux/Max). Note, however, that our submit servers only accept connections from campus networks. Off-campus connections have been disabled for security purposes. If you need to connect from off campus, you can first SSH to a computer in your department, and then SSH to our submit server. You may also be able to use a Virtual Private Network (VPN) to join the campus network when working off-campus. DoIT provides information on using a VPN.

For more detailed information on connecting to CHTC services, both logging in and transferring files, see our Connecting to CHTC guide.

Data Practices

CHTC data locations are not backed up, and users should treat CHTC compute systems as temporary storage locations for active, currently-queued computational work. Users should remove data from CHTC systems upon completion of a batch of computational work and keep copies of all essential files in a non-CHTC location. CHTC staff reserve the right to delete data from any CHTC data location at at any time, to preserve performance, and are not responsible for data loss or file system corruption, which are possible in the absence of back-ups.

Note: CHTC is not HIPAA-compliant and users should not bring HIPAA data into CHTC services. If you have data security concerns or any questions about data security in CHTC, please get in touch! We’ll be happy to discuss.

Submit Server User Policies

Because our submit servers are shared by many CHTC users, anyone with an account on CHTC's submit servers should follow the below policies, in order to keep the submit servers functional and usable by everyone:

  • Do not share accounts. We are happy to make a new account for any user. Sharing accounts is against campus policy and, therefore, CHTC policy. Accounts that we notice being shared will be immediately disabled and a meeting with the PI (faculty advisor) will be necessary to reinstate the account.
  • Do not run programs on the submit servers. The submit server is kept plenty busy just managing HTCondor jobs. Computational work, like compiling or testing code, should be submitted as HTCondor jobs. See our online guides for the best compiling practices. Small scripts and commands (to compress data, create directories, etc.) that run within a few minutes on the submit server are okay, but their use should be minimized when possible.
  • Jobs with long runtimes. There is a default run limit of 72 hours for each job queued in the HTC System, once it starts running. Jobs longer than this will be placed in HTCondor's "hold" state. If your jobs will be longer, please email us, and we'll help you to determine the best solution.
  • Submitting many jobs from one submit file. HTCondor is designed to submit thousands (or more) jobs from one submit file. If you are submitting over 10,000 jobs per submit file or want to queue more than 50,000 total jobs as a single user, please email us as we have strategies to submit that many jobs in a way that will ensure you have as many jobs running as possible without also compromising queue performance.
  • The default disk quota is 20 GB in your /home directory, as a starting point. You can track your use of disk space and your quota value, using our Quota Guide. If you need more space for concurrent work, please send an email to chtc@cs.wisc.edu.
  • Submitting jobs with "large" files: HTCondor's normal file transfer mechanism ("transfer_input_files") is good for files up to 100MB in size (or 500MB total, per job). For jobs with larger files, please see our guide on File Availability Options, and contact us to make arrangements.
  • No scheduled jobs. Local execution and job submission should be manual (using condor_submit), or use a DAG or other approved workflow tool. Do not use cron or other scripts that run on the submit server to automate job submission. Contact us if you need help with job scheduling or workflows.