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aurora_cluster:how_scheduling_works [2019/03/18 09:18]
florido [Considerations on interactive sessions]
aurora_cluster:how_scheduling_works [2019/08/27 10:28] (current)
florido [FAQ]
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   * In order to preserve the possibility to use all of the nodes when needed, these requests should be flexible enough to be changed on the fly according to needs of the members of the project   * In order to preserve the possibility to use all of the nodes when needed, these requests should be flexible enough to be changed on the fly according to needs of the members of the project
  
 +===== FAQ =====
 +
 +//These are true for both HEP and SNIC paritions, it's the overall Lunarc policy. The difference is that on the HEP nodes you only compete with users from Particle, Nuclear and Theoretical physics instead of the whole Lunarc user base on SNIC.//
 +
 +1) If I have an allocation, and I don't run for months, will I get higher prio when I then run?
 +> No, unused computing cycles within a billing month are lost. . Time not spent is gone and does not add to a "​favour bank". However, there is a sliding 30-day window, which means that you have zero usage when you resume after a long silence and will get a higher priority than those that have been running within the 30-day window. How this priority is reduced when you are running depends on the allocation.
 +
 +2) If I submit a job and noone else is running, can I get more resources than the guaranteed/​allocated one?
 +> Yes, you can use more time than allocated. There are several soft limits and a hard one with respect to aggregated usage (30 days), but the hard one is four times the allocation for small and medium allocations. There are also restrictions triggered by concurrent usage of cores, but they are all soft. There are soft limits that set the allowed number of cores to a low number, such as 20 per user and 60 per project, which becomes hard if a job is too wide.
 +
 +3) If I submit a job at the end of the billing month and it ends up in the queue, will I get an higher prio at the beginning of the next month?
 +> Not really. The 30-day window is sliding, which means that it is not tied to a calendar month. However, if you were running intensely 30 days ago, waiting in the queue a few days will erase the memory of that and if you are close to a limit, the priority can jump. The only time that you can get a clean slate despite using the system recently is when one project ends and a new one starts, because usage is not carried over when a project is renewed and gets a different project code, which typically happens once a year. 
aurora_cluster/how_scheduling_works.1552900684.txt.gz ยท Last modified: 2019/03/18 09:18 by florido

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