[Bug 1214482] [NEW] Not-grouping dependent packages in Phased Updates changes propability distribution for entire group of dependent packages.

[Marek Wrzosek]

Public bug reported:

I assume that you decided for uniform distribution in the random number
generator. If group of dependent packages is installed only when all
phased-update-percentage values (for each package) are smaller than the
present percentage on server - it will change probability distribution
for the whole group of packages.

Just run this:

figure(1)
hist(rand(1,100000))
for i = 2:10
	figure(i)
	hist(max(rand(i,100000)))
endfor

in octave and look at histograms for i>1 (i is the number of dependent
packages).

** Affects: update-manager (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1214482

Title:
  Not-grouping dependent packages in Phased Updates changes propability
  distribution for entire group of dependent packages.

Status in “update-manager” package in Ubuntu:
  New

Bug description:
  I assume that you decided for uniform distribution in the random
  number generator. If group of dependent packages is installed only
  when all phased-update-percentage values (for each package) are
  smaller than the present percentage on server - it will change
  probability distribution for the whole group of packages.

  Just run this:

  figure(1)
  hist(rand(1,100000))
  for i = 2:10
  	figure(i)
  	hist(max(rand(i,100000)))
  endfor

  in octave and look at histograms for i>1 (i is the number of dependent
  packages).

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