Lightweight Collection and Storage of Software Repository Data with DataRover

Thomas Kowark, Christoph Matthies, Matthias Uflacker and Hasso Plattner

HPI, Enterprise Platform and Integration Concepts Chair, Potsdam, Germany

ASE 2016 Demo Track

September, 5th

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DataRover

Background — Collecting Software Repository Data

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Collaboration Infrastructure

Wiki

Version Control

Issue Tracker

CIServer

…

Development Teams

use

MSR* Researchers

* MSR – Mining Software Repositories

transform

load Interlinked Data Set

extract

● How do teams develop software?● What separates good from bad teams?● How are we doing as a team?

ETL Software

■ Plugin/service-based architectures□ One plugin/service per data source□ Custom data schema□ Alitheia-Core [Gousios et al., 2009], SOFAS [Ghezzi, 2012], Sonarqube

■ Graphical ETL-Tools□ Plugin for each data source connection□ Visual creation of ETL processes□ RapidMiner, KNIME

■ Collections of Repository Data□ Pre-collected, cleansed, and interlinked data sets□ Boa [Dyer et al., 2013] with custom query language□ GHTorrent [Gousios, 2013 and ongoing], StackExchange dumps

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Related Work

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■ Why doesn’t this mining tool support my new/updated data source?□ “The development team has migrated to Gitlab”

■ How are the peculiarities of my project reflected in the standard data schema and analyses?□ “We use JIRA with custom fields”

■ Can I store this data in a graph or document database to perform network analyses or text mining?□ “Neo4J already offers the graph algorithms that I need.”□ “All my existing queries rely on MySQL.”

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Common Issues

■ Goals□ Minimal implementation effort for each data source□ Separate collection and linking□ Reuse existing implementations whenever possible□ Allow focus on linking and analysis, not data collection

■ Concepts□ Collection: Explorer (OAuth, Query Parameters) => JSON– Stackoverflow Client: ~12 LoC + logging

□ Linking: Define generic mappings using GUI– Map JSON attributes to links, new nodes or node values

□ Storage: Graph database (Neo4J)– No explicit database scheme, easily add connections at runtime

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Lightweight Data Collection — DataRover

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Data Collection — Explorers

https://bitbucket.org/tkowark/data-rover/src/b37e79847a7b08a604688133834a0592b9320b57/app/models/explorers/stackoverflow_explorer.rb

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■ Mappings: define transformations of JSON to property graph

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From JSON to Property Graphs

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Linking Data

■ Linking performed by attribute equality□ New relation indicating node similarity□ Node merging in case of equal node types

■ For Ruby-on-Rails Github repo: 2320 of 3075 users found in SO data

StackoverflowUser

GithubUser

same_as

■ Export constructed interlinked graph□ Reuse existing analysis□ Use the technology you like / are most proficient in

■ Graph Databases□ Store the graph as-is

■ Relational Databases□ One table per node Class□ Separate relation tables

■ Document stores□ One collection per node class□ Links as properties or using internal document ids

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Storing Property Graphs

■ Only storing what you really need□ Rails commit data w/o file changes (58k commits, 3k users)□ Example query: amount of commits performed by each user

■ Future Work□ User study (Mapping creation time, error-proneness, clarity, etc.)□ Measuring data import times for large datasets Christoph Matthies

Sep 5

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Evaluation (ongoing)

■ DataRover□ Lightweight data collection, only code querying□ Minimalistic data sets tailored to specific use cases□ Ease of mapping creation, visualize mappings□ Data Linkage□ Storage in different target databases

■ Try it: http://bitbucket.org/tkowark/data-rover (MIT license)□ Screencast: https://www.youtube.com/watch?v=mt4ztff4SfU□ Sample datasets: https://bit.ly/kowark-ase-16-data

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Summary

■ web developer by Hugo Alberto from the Noun Project■ Communication by Role Play from the Noun Project■ Browser by icon 54 from the Noun Project■ Mars Rover by LA Hall from the Noun Project■ discussion by Milka Dahan from the Noun Project

Picture Sources