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aurora_cluster:how_scheduling_works [2019/03/18 09:17] florido [Considerations on interactive sessions] |
aurora_cluster:how_scheduling_works [2019/03/18 09:18] florido [Considerations on interactive sessions] |
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If the cluster is busy, requesting an interactive session may take time and fail. The scheduler will happily schedule resources for a user, but if the user asks for an interactive session with say 6 cores and there is no machine with 6 cores free, the scheduler cannot fulfil the request at the moment. | If the cluster is busy, requesting an interactive session may take time and fail. The scheduler will happily schedule resources for a user, but if the user asks for an interactive session with say 6 cores and there is no machine with 6 cores free, the scheduler cannot fulfil the request at the moment. | ||
- | The scheduler treats an interactive job the same as a batch job, queueing it with the FIFO strategy described above. However, an exception to the FIFO scheduling appears when a parallel job is waiting for other jobs to finish and release resources. Then a short job can be promoted ahead of the queue, if it fits into an empty slot that is reserved for later use by the parallel job, so called //backfill//. Thus, queueing interactive jobs with shorter wall times have a higher probability of starting earlier. | + | The scheduler treats an interactive job the same as a batch job, queueing it with the FIFO strategy described above. However, an exception to the FIFO scheduling appears when a parallel job is waiting for other jobs to finish and release resources. Then a short job can be promoted ahead of the queue, if it fits into an empty slot that is reserved for later use by the parallel job, so called //backfill//. |
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+ | Thus, queueing interactive jobs with shorter wall times have a higher probability of starting earlier. | ||