Aptpbo fosdem

IntroductionAPT-PBO

Experimental ResultsConclusions

APT-PBO: improving the SoftwareDependency Problem using Pseudo-Boolean

OptimizationFOSDEM 2011 - Brussels

Paulo Trezentos

February 6, 2011

Trezentos APT-PBO 1/ 23

IntroductionAPT-PBO


Agenda

1 IntroductionProblem

2 APT-PBOArchitectureAlgorithm

3 Experimental ResultsUnmet dependencies analysisMeta-installers performanceSolutions assessmentMulticriteria

4 Conclusions


IntroductionAPT-PBO


Problem

Agenda




4 Conclusions


IntroductionAPT-PBO


Problem

Installing Linux packages (software components) is...

XKCD Webcomics, http://xkcd.com/754/


IntroductionAPT-PBO


Problem

Introduction to the problem

Relevance:Installation process is critical for Operating Systemsdissemination

Problem:It is often reported that problems of broken dependenciesbetween software packages in Linux

Solution:Use SAT to solve dependencies or, better, use PBO tochoose between solutions

Related work:EDOS, MANCOOSI, Opium / Linspire, SuSE Libzypp,Eclipse P2 / SAT4J,...


IntroductionAPT-PBO


Problem







IntroductionAPT-PBO


Problem







IntroductionAPT-PBO


Problem







IntroductionAPT-PBO


Problem

Dependencies solving

door

engine

2

3tyre

window

2

2

1conflicts

glass

glass

wheelcar 2

2

1

turbo 1

1

2

2

0

11

Install car


IntroductionAPT-PBO


Problem

Dependencies solving

door

engine

2

tyre

window

2

1conflicts

glass

glass

car 2

1

turbo 1

2

0

11

2

23

wheel

1

2

Install carNeed to install the dependencies / avoid conflictsNP-problem


IntroductionAPT-PBO


ArchitectureAlgorithm

Agenda




4 Conclusions


IntroductionAPT-PBO



APT-PBO Architecture

apt-pbo install car

[installed packages]

pboinstall: encoding of the problem

PBO solver: external solverParsing / processing: analyse the solution and iterateapt-get install: install packages


IntroductionAPT-PBO




apt-pbo install car


pboinstall: encoding of the problemPBO solver: external solver

Parsing / processing: analyse the solution and iterateapt-get install: install packages


IntroductionAPT-PBO




apt-pbo install car


pboinstall: encoding of the problemPBO solver: external solverParsing / processing: analyse the solution and iterate

apt-get install: install packages


IntroductionAPT-PBO




apt-pbo install car


pboinstall: encoding of the problemPBO solver: external solverParsing / processing: analyse the solution and iterateapt-get install: install packages


IntroductionAPT-PBO



APT-PBO Algorithm

Require: Package to install p1, Pol1: repeat2: (f , c)← call_pboinstall(p1, Pc , Pol , R, PI)3: S ← call_solver(f , c)4: Pc ← 05: for all pi ∈ S such that pi = 0 do6: Pc ← check_rdeps(pi)7: end for8: for all pj ∈ S such that pj = 1 do9: Pc ← check_rconfs(pj)

10: end for11: until Pc = 012: return f , c


IntroductionAPT-PBO



MulticriteriaIf we try to satisfy different criteria, we have a MCDM(Multicriteria Decision Making problem)

APT-PBO integrates different objective function as amultiobjective problem (MOP) and transforming into asingle objective problem through weighted sumscalarization:

min3∑

k=1

Wk · fk (P)

and therefore:

min (Wr · f1(P) + Wp · f2(P) + Wv · f3(P))


IntroductionAPT-PBO



MulticriteriaIf we try to satisfy different criteria, we have a MCDM(Multicriteria Decision Making problem)APT-PBO integrates different objective function as amultiobjective problem (MOP) and transforming into asingle objective problem through weighted sumscalarization:

min3∑

k=1

Wk · fk (P)

and therefore:

min (Wr · f1(P) + Wp · f2(P) + Wv · f3(P))


IntroductionAPT-PBO


Unmet dependencies analysisMeta-installers performanceSolutions assessmentMulticriteria

Agenda




4 Conclusions


IntroductionAPT-PBO



Unmet dependencies analysisksplash

kdelibs4c2a libc6 libgcc1 libstdc++6 kdebase-data libx11-6 libxext6

3.5.9.dfsg.1-6 4.2.2-1

Meta-installer Possible No WrongSolutions Solutions Solutions

Apt-get 591 123 0Aptitude 713 0 1Smart 714 0 0Apt-pbo 714 0 0


IntroductionAPT-PBO



Meta-installers performance

00-00

00-02

00-04

00-06

00-08

00-10

00-12

00-14

0 20 40 60 80 100 120 140

Exec

uti

on t

ime

(sec

onds)

Problem size (# installed packages)

apt-getaptitude

smartapt-pbo

Meta-installer Average Time Standard DeviationApt-get 00:00.21 00:00.17Aptitude 00:00.62 00:00.15Smart 00:02.63 00:00.25Apt-pbo 00:03.77 00:01.91


IntroductionAPT-PBO



Solutions assessment

Each package transaction can include installation, update,removal or downgradeIn 1.000 package transactions, how each meta-installerbehaves?

Tool Installed Updated Removed Down-graded

apt-get 7,766 17 12 0aptitude 8,423 18 161 464smart 7,786 92 124 479PBO freshness 6,808 20,449 25 567PBO removal 7,767 11 162 443PBO number 7,729 13 102 500


IntroductionAPT-PBO



Solutions assessment

Apt-get

Aptitude

Smart

PBO

-Freshness

PBO

-Rem

oval

PBO

-Num

ber

% o

f to

tal

InstallUpdatesRemoveDowngrade


IntroductionAPT-PBO



Multi-criteria

In APT-PBO, varying the weights, we can have differentsolutions.

For example, varying freshness weight we can obtaindifferent solutions for package at-spi:


IntroductionAPT-PBO



Multi-criteria

In APT-PBO, varying the weights, we can have differentsolutions.For example, varying freshness weight we can obtaindifferent solutions for package at-spi:

Aggressive ConservativeInstall 9 37Updates 35 35Remove 1 0Downgrade 7 10Time 00:19.45 00:17.37


IntroductionAPT-PBO



ap-spi - conservative freshness

To avoid the removal of “file-roller” we perform theinstallation of 28 extra-packages

libgnomevfs2-0

2.22

libhal1

0.5

libgconf2-4

2.26 -> 2.22

libbonobo2-0

2.22

conflicts < 2.24 at-spi

1.22

libnautilus-extension1

2.26 ->2.20

file-roller

2.26 ->2.22

breaks < 2.24

...+24

..+2breaks < 2.24


IntroductionAPT-PBO



ap-spi - agressive freshness

With “just” one removal of “file-roller” with avoid theinstallation of 28 packages and the downgrade of 3.

libgconf2-4

2.26 -> 2.22

libbonobo2-0

2.22

conflicts < 2.24 at-spi

1.22

file-roller

2.26 ->2.22

libnautilus-extension1

2.26

breaks < 2.24


IntroductionAPT-PBO


Agenda




4 Conclusions


IntroductionAPT-PBO


Conclusions

APT-PBO is a freely available tool (GPL) that can betested, available for Debian, Mandriva and Caixa Magica

PBO encoding proved to be suitable for the problem andprovides extra-flexibility compared with SAT toolsMulti-criteria is a desirable and achievable optionPerformance is an issue for large repositories and somecombination of weights.


IntroductionAPT-PBO


Conclusions

APT-PBO is a freely available tool (GPL) that can betested, available for Debian, Mandriva and Caixa MagicaPBO encoding proved to be suitable for the problem andprovides extra-flexibility compared with SAT tools

Multi-criteria is a desirable and achievable optionPerformance is an issue for large repositories and somecombination of weights.


IntroductionAPT-PBO


Conclusions

APT-PBO is a freely available tool (GPL) that can betested, available for Debian, Mandriva and Caixa MagicaPBO encoding proved to be suitable for the problem andprovides extra-flexibility compared with SAT toolsMulti-criteria is a desirable and achievable option

Performance is an issue for large repositories and somecombination of weights.


IntroductionAPT-PBO


Conclusions

APT-PBO is a freely available tool (GPL) that can betested, available for Debian, Mandriva and Caixa MagicaPBO encoding proved to be suitable for the problem andprovides extra-flexibility compared with SAT toolsMulti-criteria is a desirable and achievable optionPerformance is an issue for large repositories and somecombination of weights.


IntroductionAPT-PBO


Future work

Better tuning of PBO encoding and work with PBO solverresearchers to improve performance issues

Support new features like using APT-PBO for removals,etallEnhance interactive mode


IntroductionAPT-PBO


Future work

Better tuning of PBO encoding and work with PBO solverresearchers to improve performance issuesSupport new features like using APT-PBO for removals,etall

Enhance interactive mode


IntroductionAPT-PBO


Future work

Better tuning of PBO encoding and work with PBO solverresearchers to improve performance issuesSupport new features like using APT-PBO for removals,etallEnhance interactive mode


IntroductionAPT-PBO


More information

Paulo Trezentos, Ines Lynce, and Arlindo L. Oliveira.Apt-pbo: solving the software dependency problem usingpseudo-boolean optimization. In ASE 10: Proceedings ofthe IEEE/ACM international conference on Automatedsoftware engineering, pages 427-436, New York, NY, USA,2010. ACM

http://aptpbo.caixamagica.pt


IntroductionAPT-PBO


More information

Paulo Trezentos, Ines Lynce, and Arlindo L. Oliveira.Apt-pbo: solving the software dependency problem usingpseudo-boolean optimization. In ASE 10: Proceedings ofthe IEEE/ACM international conference on Automatedsoftware engineering, pages 427-436, New York, NY, USA,2010. ACMhttp://aptpbo.caixamagica.pt


IntroductionAPT-PBO


Thank you.

Questions.


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Aptpbo fosdem