Talk:Bellatrix scheduler requirements

Reference period
With reference period I refer to the time span used by the fair-share scheduler to decide the priority of new submitted jobs.

There are three ways for the reference period to be calculated that come to my mind. For the examples below, I assume for simplicity a period of 1 month (30 days).


 * A: The reference period that is taken into account is the previous 30 days: if today is the 20th of June, then the period is 21st May-19th June.
 * B: The reference periods are fixed, say to calendar months, and the reference period is the previous calendar month; if today is the 20th of June, then the period is 1st May-31th May.
 * C: The reference periods are fixed, and the reference period is the current calendar month from its first day to today: if today is the 20th of June, then the period is 1st June-19th June.

My personal feeling is that:


 * method A is probably the best for private queues: if I don't use the system for one month, I expect to have a very high priority the next time that I submit a job.
 * method B is the worst: if I don't use the machine in May, then in June I have the max priority for the whole month; even if in the first days of June I use the whole machine, in the following days I still have the same high priority because the reference period is always May.
 * method C is probably more useful for the shared queue, where the machine is sold for a given time span. The length of the reference period can then be the selling period (6 months?) or a divisor, say 2 or 3 months, and at the end of the reference period the past history is reset.

--Giovanni Pizzi (THEOS) 14:50, 3 September 2013 (CEST)

Length of the reference period
My feeling is that, for private queues, the length of the reference period should be relatively short, say 1 or 2 weeks: if I go away for a conference and I don't submit calculations, or if I spent a few weeks debugging/developing a code, when I go back to bellatrix to submit I'd like to have a fairly high priority.

On the shared nodes, probably the period should be longer, even if I believe that 6 months is too much. I'd rather use a period of 2 or 3 months.

--Giovanni Pizzi (THEOS) 14:50, 3 September 2013 (CEST)