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
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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
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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