Metrics for Large Software Development Teams Jesus M. Gonzalez-Barahona [email protected] @jgbarah Bitergia / LibreSoft (URJC) http://speakerdeck.com/jgbarah/ Metrics Day at Chalmers University of Technology Gothenburg (Sweden), November 10th 2016 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 1 / 69
Structure of the presentation 1 A bit of context 2 Dealing with dynamic complexity 3 Sources of information 4 Activity / size 5 Remaining code 6 Performance 7 Demographics 8 Diversity in FOSS development 9 GrimoireLab: tools for software development analytics 10 Final remarks Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 2 / 69
Me and my two hats Uni Rey Juan Carlos: LibreSoft research team Understanding free, open source software Data analytics approach Bitergia: From research to the real world Understanding software development Data analytics approach http://gsyc.es/~jgb Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 4 / 69
The company The software development analytics company dashboards reports consultancy ... http://bitergia.com Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 5 / 69
The book Evaluating FOSS Projects: Work in progress Free / open book Fork and play! https://jgbarah.gitbooks.io/evaluating-foss-projects/ Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 6 / 69
Recommendations Open your laptop Download the slides (they have links) Visit Cauldron.io and produce your own dashboard Play with the dashboards Understand the interpretations behind the numbers http://cauldron.io Code: OWL2016 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 7 / 69
The Cauldron http://cauldron.io/dashboards/elastic Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 8 / 69
Example: OPNFV dashboard http://opnfv.biterg.io Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 9 / 69
Projects may be large and complex... and dynamic It’s difficult to... ...track what’s happening ...understand why it’s happening ...react quickly ...evaluate results of reaction If data is available analytics may come to the rescue Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 12 / 69
A continuous process Figure out your interest Find out available data Define key parameters Monitor, understand, detect deviations Act to correct, improve Track results Measure → Monitor → Act Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 13 / 69
A continuous process (example) Case: Overall development activity Interest: activity Data: changes to code, tickets Parameters: commits, tickets closed Monitoring: charts, numbers Observation: numbers declining Action: allocate more developer effort Track results... Measure → Monitor → Act Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 14 / 69
Source code management Centralized or client/server: CVS, Subversion Decentralized: git, Mercurial, Bazaar, etc. Today: most of them accessible through git... but not always the information is what appears to be (eg: branches in Subversion and git) Can be integrated with other tools: Gerrit, GitHub, etc. Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 17 / 69
Issue tracking Many different systems: Bugzilla Jira GitHub issues Phabricator RedMine Trac ... Each with a different model, data, operations... Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 18 / 69
Code review More and more projects using it Usually: peer review pre-merge change review Different methods: Mailing lists (eg: Linux) Gerrit (eg: OpenStack) GitHub pull requests (eg: ElasticSearch) or even Jira, Bugzilla... Usually, references to tickets and commits Much of the control on the software lies here Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 19 / 69
Asynchronous communication Mailing lists: Mailing lists systems (Mailman) Google Groups Mailing list archivers (Gmane) Forums: too many to mention Question/Answer sites: StackOverflow, Askbot Information is always archived Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 20 / 69
Synchronous communication Systems: Traditionally: IRC Nowadays: Slack & many others Not always text/based (eg: videoconferences) Notes: In many cases, lack of archives Privacy concerns: considered informal communication Difficult to track identities Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 21 / 69
Tracking involved parties Development is much more than developers (this is explicit in FOSS & inner sourcing) Developers: all repositories Contributors: issue tracking, async communication Users: async communication, ... Ecosystem: difficult to track Software may include beacons: tracking usage Needed: tracking identities in different data sources Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 22 / 69
Activity / size Many different aspects of activity: committing patches: source code management system reporting, commenting or fixing bugs: issue tracking system submitting patches or reviewing them: code review system sending messages: async or sync communication systems Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 24 / 69
Activity / size (most common cases) Parameters reflecting activity for a certain period. People active for a certain period. Evolution of any of them. Trends for any of them. Difficult to compare between projects Interesting to compare inside project (different subprojects, different time frames) Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 25 / 69
Activity / size (many facets) http://cauldron.io/dashboards/elastic Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 26 / 69
Activity / size (many facets) http://s.bitergia.com/db-fosdem16 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 27 / 69
How old is code [Linux kernel, July 2016, lines in C files by age] http://linux.biterg.io Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 29 / 69
How old is code (2) [Linux kernel, July 2016, C files by last commit] http://linux.biterg.io Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 30 / 69
How old is code (3) [Linux kernel, July 2016, C files by first remaining commit] http://linux.biterg.io Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 31 / 69
How old is code? drivers/net in Linux Age of lines (data of authorship, “.c” files) From top left, clockwise: Wireless, USB, IRDA Ethernet Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 32 / 69
Backlog (evolution over time) Example: backlog of open issues. http://cauldron.io/dashboards/elastic Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 34 / 69
Efficiency Example: closed / opened tickets per quarter Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 35 / 69
The complete coding process From idea to implementation Story, design Ticket(s) Code review Automated testing Commit in code base The OpenStack case Blueprint (if feature), Launchpad Ticket (bug, feature), Launchpad Code review, Gerrit Automated testing, Jenkins Commit in code base, Gerrit, Git Similar cases: GitHub, GitLab, Atlassian Requires discipline in the developing team Requires enough traces in the repositories Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 41 / 69
The many identities of anyone The repository level. The class of repository level. The project level. The global level. Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 43 / 69
Demographics: The aging chart Attraction Retention Newcomers Expertise Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 44 / 69
Demographics: Contributors funnel Communities of volunteers “Peripheral”: activities (questions, reporting bugs) Small contributions: answers, bug fixes change proposals Core: design, feature implementation, bug fixes Inner source Questions, reports, etc. in public (no more coffee machine meetings) Moving to develop: answers, bug fixes change proposals Core: design, feature implementation, bug fixes, mentorship Finding traces, visualizing career evolution Assessments & forecasts of available expertise Identification of success stories Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 45 / 69
Demographics: Mentorship Helping newcomers, helping people from other areas Usually linked to bug fixing and code review Who is helping others to improve their skills? Who are benefiting more from the help of others? Who are newcomers, and who of them are not receiving mentorship? When a newcomer may convert into mentor? Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 46 / 69
Diversity: geographical information (time zones) http://cauldron.io/dashboards/elastic Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 48 / 69
Diversity: geographical information (GitHub profiles) Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 49 / 69
Diversity: affiliation http://s.bitergia.com/db-fosdem16 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 50 / 69
Diversity: Apache Pony Factor In words of Daniel Gruno: We [the ASF] created a term we have coined “Pony Factor” (because ASF is full of ponies, or people who think they are ponies). Pony Factor (PF) shows the diversity of a project in terms of the division of labor among committers in a project. Pony Factor is determined as: “The lowest number of committers whose total contribution constitutes the majority of the codebase” https://ke4qqq.wordpress.com/2015/02/08/pony-factor-math/ Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 51 / 69
Diversity: Bitergia Elephant Factor Projects can benefit from powerful collaborations from companies (elephants). The elephant factor shows the diversity of a project in terms of the division of labor among companies (by mean of developers affiliated with them). Elephant factor is determined as: “The lowest number of companies whose total contribution (in commits by their employees) constitutes the majority of the commits” Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 53 / 69
Diversity: Code “owned” “The land belongs to its workers” Emiliano Zapata Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 55 / 69
Diversity: Code “owned” The code changes over time. The current version is “owned” by the people who produced it. The code “belongs” to those who wrote it. Zapata factor (work in progress): “The lowest number of developers for whom the total number of lines of code they “own” (were last touched by them) constitutes the majority of the lines of code” Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 56 / 69
Diversity: Code “owned” [Linux kernel, July 2016, Zapata factor: 200] Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 57 / 69
Diversity: Code “owned” The code “belongs” to companies who employ developers changing it. United Fruit factor (work in progress): “The lowest number of companies for whom the total number of lines of code they “own” (were last touched by their employees) constitutes the majority of the lines of code” Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 58 / 69
Diversity: Gender gap Commits by women: 6.8% (4 Kcommits) Women: 9.9% (330 developers) Linux kernel, Nov 2015 – Oct 2016 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 59 / 69
GrimoireLab: tools for software development analytics Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 60 / 69
GrimoireLab Perceval: data retrieval Arthur: retrieval orchestration GelK: enrichment SortingHat: identity management ElasticSearch (*): database for storing everything Kibiter: dashboard (light fork of Kibana) Panels: visualizations for Kibiter http://grimoirelab.github.io (*) Not a part of GrimoireLab Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 62 / 69
Room for improvement Many other aspects... explore your own Refine what is important Explore new ways of making data useful Tell interesting stories based on data Visualization is very important Higher-order metrics Simplify results, make them meaningful Can we characterize many aspects with a small set of metrics? Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 65 / 69
Summary You cannot improve what you cannot measure Fortunately, you can measure a lot of things... http://bitergia.com http://grimoirelab.github.io http://speakerdeck.com/jgbarah Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 66 / 69
A moment for a commercial: Join us at MSR 2017!! http://2017.msrconf.org 14th International Conference on Mining Software Repositories Co-located with ICSE Buenos Aires, Argentina Save the dates: May 20-21 2017 Start the conversation!!! #msr17 Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 67 / 69
c 2016 Bitergia Some rights reserved. This presentation is distributed under the “Attribution-ShareAlike 3.0” license, by Creative Commons, available at http://creativecommons.org/licenses/by-sa/3.0/ Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 68 / 69
Credits (1) “Man With Two Hats” Statue by Henk Visch, located in Otawa, Canada Picture by Lezumbalaberenjena in Wikimedia Commons License: Public domain https://commons.wikimedia.org/wiki/File: Man_With_Two_Hats_Ottawa_Statue_by_lezumbalaberenjena.jpg “Crowd at FOSDEM 2008” by Jes´ us Corrius License: CC Attribution 2.0 http://www.flickr.com/photos/jcorrius/2302302707/ “Emiliano Zapata” License: Public Domain Jesus Gonzalez-Barahona (Bitergia) Metrics for Large Software Development Teams Metrics Day 2016 69 / 69
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