Hi Don, Ah! That makes sense. Thanks for the explanation.
-Aaron On Thu, May 26, 2011 at 12:39 PM, Lipari, Don <[email protected]> wrote: > Aaron, > > > > You have discovered a case where the design/implementation outpaced the > documentation. Originally the usage was normalized to the theoretical > maximum usage subject to half-life decay as documented. But we found that, > for under-utilized systems, each user’s normalized usage was very low, which > gave them higher fair-share factors. In this circumstance, the result was > that fair-share factors for all users tended to get crowded toward 1.0 and > one would have to increase the fair-share weight to resolve them. > > > > By changing to make the usage normalized to total actual usage, we > prevented this artifact. It made the code a little simpler as well. With > this change, we still maintain “fairness”. However, users may notice minor > variations in the normalized usage that gets reported based on usage outside > their accounts. This variation will diminish substantially the more fully a > cluster is utilized or by increasing the PriorityDecayHalfLife configuration > value. > > > > I will update the html page to reflect the newer formula. > > > > Don > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Aaron Knister > *Sent:* Wednesday, May 25, 2011 7:22 PM > *To:* slurm-dev > *Subject:* [slurm-dev] Normalized usage question > > > > The multifactor priority documentation seems to suggest that the normalized > usage is calculated based on the cluster's available CPU time. However, in > practice it seems to be based on the summation of all raw usage. I'm getting > ready to implement fairshare priorities and am wondering which is the case. > The former would be ideal as that way the fairshare values in the output of > sshare won't flip flop based on usage outside of a given account. Of course, > it's always possible something is borked in my testing setup :) >
