This is something which i found unintuitive when looking at the factors for OOBs. Metrics which had very narrow high/low ranges could generate OOBs with very large factors from values just above or below their high/low, while metrics with larger ranges generated OOBs with smaller factors, even though the values were much further away from their high/low. See conversation below for more details... (10:45:06 AM) ccrouch: pilhuhn: so I'm looking at some oobs (10:45:28 AM) ccrouch: trying to work out what the factor is now? (10:45:48 AM) ccrouch: "Out of range factor (%)" (10:46:34 AM) pilhuhn: factor is the same -- the issue you are probably seeing is that the one 5.2m is not the same as the other 5.2m So the band is perhaps really 5.1999m - 5.20001m but our code displays it as 5.2 (10:46:47 AM) ccrouch: right, i think i get it (10:46:50 AM) pilhuhn: go to the big chart (click on the metric name) and see what it says for the band (10:47:10 AM) ccrouch: it produces some arguably unintuitive results (10:47:14 AM) ccrouch: for example (10:47:27 AM) ccrouch: 4.9m - 4.9m 4.2m 8110 (10:47:45 AM) pilhuhn: for line 2 it is (84-3) / (3-2) = 81 / 1 = 81 = 8100 % (10:47:55 AM) ccrouch: 4.2minutes is 8110% out of the range (10:48:43 AM) ccrouch: around 4.9minutes (10:48:43 AM) ccrouch: and then (10:48:43 AM) ccrouch: 2.0ms - 3.0ms 84.0ms 8100 (10:49:10 AM) ccrouch: 84ms is 8100% out of the range between 2 and 3 (10:49:23 AM) ccrouch: i agree the math is correct :-) (10:50:00 AM) ccrouch: i'm just arguing is something that goes from 4.9 to 4.2 more out of bounds than something that goes from 2 to 84 (10:50:36 AM) mazz: no ccrouch. 2->84 is more OOB (10:50:38 AM) pilhuhn: ccrouch: that is because the band of the 4.2 one is so narrow (10:50:49 AM) mazz: assuming the band is small too (10:50:59 AM) ccrouch: (10:50:36 AM) mazz: no ccrouch. 2->84 is more OOB (10:50:59 AM) ccrouch: not using the factors as they are today (10:51:06 AM) pilhuhn: 4.2 is not 4.2 but in reality it is something like 4.19999 or 4.20005 (10:51:07 AM) ccrouch: pilhuhn: yep (10:51:23 AM) ccrouch: right, i understand why its like this (10:51:38 AM) ccrouch: i'm just saying its somewhat counter intuitive (10:51:59 AM) pilhuhn: ccrouch: Try to get the raw band data from the big charts page. If this shows the same, try to get it from the db -- we can still argue if we shall ignore those bands that are too narrow (10:52:24 AM) ccrouch: hmm thats an interesting option (10:52:48 AM) ccrouch: ignoring the very narrow bands (10:53:03 AM) pilhuhn: But dividing through the band size is the only way to be able to compare very big metrics (100s of MBs ) with small ones (single digits) (10:56:17 AM) ccrouch: pilhuhn: agreed about the need for some sort of banding (10:56:49 AM) ccrouch: but very narrow bands have disproportionately big impact on the fact (10:56:52 AM) ccrouch: factor (10:57:18 AM) ccrouch: well they have the same impact as the metric which is actually out of bounds i guess (10:57:44 AM) pilhuhn: yes (10:58:10 AM) pilhuhn: I mean if the band is 4.21 - 4.22 and the metric is 4.3 the factor will be small too (10:58:41 AM) ccrouch: yep, but the issue is 4.21001 - 4.21002 and the metric is 4.3 (10:59:01 AM) ccrouch: the factor will be 1000x what it was previously (10:59:38 AM) ccrouch: but to me its not very much more out of bounds (11:00:34 AM) pilhuhn: then draw it on a sheet of paper, in a unit where high and low bounds are 10cm away and then try to put 4.3 on that sheet too :) (11:00:39 AM) ccrouch: infact with a band of 4.2199999-4.220000 and the metric of 4.3, its arguable no more out of bounds than before (11:01:10 AM) pilhuhn: And then after that put a band 100,150 with an outlier of 200 next to that -- also the bounds on the same place on the sheet as before (11:01:11 AM) ccrouch: can we do something that takes into account the bound values when calculating the band? (11:02:07 AM) pilhuhn: I don't want to change this now. We can add a FR for 2.3 (11:02:48 AM) ccrouch: we're going to get support case on this :-) (11:03:32 AM) pilhuhn: I am sure we will - but we will no matter what algorithm we use
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-1756
mass add of key word FutureFeature to help track