The Onion Patch: Migration in Open Source Ecosystems

Corey Jergensen*Anita Sarma*

Patrick Wagstrom+

* University of Nebraska, Lincoln + IBM TJ Watson Research Center

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Not sure if this a paper about

ogres, software development,or cooking

September 7, 2011

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This Talk in One Slide

• The Onion Model proposed a model for developers to join individual projects

• Ecosystems change the project landscape• Similar social norms and technical

requirements across projects in an ecosystem lower barrier to entry

• We examine how an ecosystem alters the ways in which developers join projects

September 7, 2011

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Spoiler Alert – Our Findings

• There are different progression paths that can be followed

• Tenure does not necessarily mean more central contribution

• Different Classes of Committers Exist• Little concrete evidence of the Onion model

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Overview

• The Onion Model• Primary Research Questions• Our data• Progression paths• Effect of tenure on commit centrality• Committer classes• Implications

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Layers – Like an Onion

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Users

Contributors

Core

Mailing Lists

Bug Trackers

Code

Social

Socio-Technical

Technical

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Research Questions

• Does Migration Occur in Ecosystems?• When a developer migrates, can they kickstart

participation with pre-existing knowledge?• In interconnected ecosystems, what factors

affect contribution type and quality?

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The GNOME Project

• We examined subset of six successful projects

• Between 369 and 1085 people active across email, bug tracker, and code repository

• Both GUI tools and underlying libraries

• Up to 10 years of historySeptember 7, 2011

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Does Migration Exist?

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369

716 541

475

6901085

120

122

169

166

112

107

162 123

181

133164

69

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Progression Paths

Mail Bugs Code

Release 1 Release 2 Release 3

Mail Bugs Code

Bugs Mail Code

Code

Bugs Code

Socio Technical

Accelerated

Tech Social

Technical

Source OnlySeptember 7, 2011

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Findings of Progression Paths - Project

Social-techAcceleratedTech-socialTechnicalSource Only

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Findings of Progression Paths - Ecosystem

Social-techAcceleratedTech-socialTechnicalSource Only

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Centrality of Commits

• Difference between being a committer and being a core committer– Previous research has shown that core does most

of the work on most projects• Once becoming a committer, what factors

affect relationship to core?

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Commit 1

Commit 2

Calculating Source Code Centrality

foo.c bar.c

baaz.cAlice

Bob

quux.c

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Time

Cent

ralit

yTenure != Centrality

Simple Story• Mail Activity +• Tracker Activity +• Project Experience -

Detailed Story• Mail Activity +• Tracker Activity +• New to Project +• Middle Aged +• Experienced ???

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Major Factors Affecting CentralityArtifacts Created•Source Commits•Bugzilla Activity & Comments•Mailing List Messages

Single Project Experience•Prior Experience•Total Ecosystem Experience•Project Experience

Broad Social Experience•Translation Commits•Mailing List Messages•Prior Experience•Ecosystem Experience•Project Experience•Active Experience

Technical Medium Experience•Source Commits•Mailing Lists•Tracker Activity•Prior Experience•Active Experience

Component 1 Component 2

Component 3 Component 4

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Kik ezek az emberek?

• Translators!• Common infrastructure used across projects• “Parachute in” to implement

internationalization• Individual translators can work only on the

translation files without needing to hack project code

Wer sind diese Leute?Who are these people?谁是这些人？

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Implications?• Open Source is kinda like an onion, but for the most part it isn’t• There is a need for project stewards as well as code warriors• Common Infrastructure enables ecosystem migration

• Ecosystems have changed our views– When hiring

• question should not be “What have you done on project X”? • Rather “Show me everything that you’ve done on Github.”• StackExchange for example accrues karma across all boards

– For researching• Is socialization process taking place through social media?

– Are layers of the onion model being created outside of traditional Software Engineering artifacts

• Is karma/credits already known intrinsically by the community and leading to following?

September 7, 2011