Big Days

'Big Days’ for large-scale runs on JUWELS BOOSTER

JSC will offer ‘Big Days’ on JUWELS BOOSTER to facilitate large-scale runs driven by current demand. During the ‘Big Days’ the full system will be reserved for the execution of large-scale jobs.

When?
Based on demand, offered slots are typically Tuesdays starting 9.00 AM CET.

Who can participate in the ‘Big Days’?
All JSC users with jobs running on 384 nodes or more.

How do I submit jobs to run as part of the ‘Big Days’?
Please get in touch with SC support by writing an email (by Sunday midnight) to sc@fz-juelich.de with 'subject: Big Days - <project ID>' providing us with information (if possible) on the estimated

1. number of jobs
2. number of nodes per job
3. runtime per job

you intend to run. Please, also provide information on the type of your jobs: e.g. production, scaling, performance testing, etc. If you are part of JUREAP, please provide us with your JUREAP ID.

We will create a reservation in which you have to submit into. The details of the reservation will be shared with you after you have sent us the requested information above. The reservation is common to all users & projects who submit as part of the ‘Big Days’ and the scheduling is done by SLURM. Please submit your jobs to the queue Monday evening for a smooth operation.

What about budget?
‘Big Days’ do not come with their own budget. Execution of your jobs as part of the ‘Big Days’ is contingent upon your project having enough budget available for the planned runs. If your projects works with monthly quotas and does not have enough compute time budget available in the 3-month window, while enough budget overall, please inform us so when you get in contact.

I am not running as part of the ‘Big Days’ - how does it affect me?

When is the system available again for execution of regular jobs?
The reservation is removed and normal operation resumes after the execution of the last job scheduled as part of the ‘Big Days’ has finished. Depending on demand, this can be 2h after the reservation started or only the next day. To monitor whether the reservation is still active, please consult the status page. We appreciate your patience.

How can I make use of the draining phase for my jobs?
Before the reservation starts, the Slurm job scheduler begins to empty the system by not allowing new regular jobs to start if they are expected to finish only after the start of the reservation Tuesday 9.00 AM. If your jobs fit into a shorter timeframe, please change the max. allowed runtime/walltime for your jobs through the Slurm option --time=. If this is smaller then the remaining time until the reservation and if there are enough idling nodes available and simply waiting for the beginning of the reservation, your job will be scheduled to run before the reservation, exploiting the 'backfilling' mechanism. We strongly encourage users to make use of this mechanism to make good use of the system, specially for short-lived jobs that are often used in large scale testing.

Last Modified: 08.11.2024