refactoring for software architecture smells - international workshop on refactoring - sept 2016
TRANSCRIPT
Refactoring for Software Architecture Smells
International Workshop on Refactoring Singapore, Sept. 4 2016
Ganesh Samarthyam CodeOps [email protected]
www.codeops.tech
Refactoring for Software Architecture Smells
“Functional Chaos!”
City Metaphor for Refactoring
“Cities grow, cities evolve, cities have parts that simply die while other
parts flourish; each city has to be renewed in order to meet the needs of its populace… Software-intensive systems
are like that. They grow, they evolve, sometimes they wither away, and
sometimes they flourish…”
Grady Booch in the foreword for “Refactoring for Software Design Smells: Managing Technical Debt”, Girish Suryanarayana, Ganesh Samarthyam, Tushar Sharma, Morgan Kaufmann/Elsevier, 2014.
Code refactoring
margin = c.getMargin();
if (c instanceof AbstractButton) {
margin = ((AbstractButton)c).getMargin();
} else if (c instanceof JToolBar) {
margin = ((JToolBar)c).getMargin();
} else if (c instanceof JTextComponent) {
margin = ((JTextComponent)c).getMargin();
}
Refactoring design smells
Earlier (relatively) mature work
Tangles in JDK
Refactoring for Architecture Smells
Remove one of the dependencies
Change dependency direction Move one of the dependencies
Architectural refactoring
Architectural refactoring …
Key reasons for architecture refactoring
Business needs
Increase feature velocity
Address architecture
decay
Realizing NFRs
Modernize
Reduce costs
Increase feature velocity
Reduce costs
Address architecture decay
Modernize
Refactoring Windows
Refactoring Windows
Refactoring Windows
“A large number of dependencies at the module level could be reduced and optimized to: * make modular reasoning of the system more efficient* maximize parallel development efficiency* avoid unwanted parallel change interference* selectively rebuild and retest subsystems effectively”
Refactoring performed to reduce and optimize dependencies - by creating and enforcing layering
Source: Kim, Miryung, Thomas Zimmermann, and Nachiappan Nagappan. "An Empirical Study of RefactoringChallenges and Benefits at Microsoft." IEEE Transactions on Software Engineering 7 (2014): 1-1.
Refactoring Windows: Significant Characteristics
Refactoring decisions made after substantial analysis of existing dependency structure
Refactoring effort was centralized and top down with designated team for refactoring
Use of custom refactoring tools (MaX) and processes (quality gate check)
Source: Kim, Miryung, Thomas Zimmermann, and Nachiappan Nagappan. "An Empirical Study of RefactoringChallenges and Benefits at Microsoft." IEEE Transactions on Software Engineering 7 (2014): 1-1.
Refactoring Windows
Source: Kim, Miryung, Thomas Zimmermann, and Nachiappan Nagappan. "An Empirical Study of RefactoringChallenges and Benefits at Microsoft." IEEE Transactions on Software Engineering 7 (2014): 1-1.
Refactoring JDK
Tangles in JDK
Copyright © 2015, Oracle and/or its affiliates. All rights reserved
Copyright © 2015, Oracle and/or its affiliates. All rights reserved
Copyright © 2015, Oracle and/or its affiliates. All rights reserved
Project Jigsaw in Java 9
Modularize JDK & JRE
Hide platform internal details such as sun.misc
Provide a module system for Java developers
Related work
"architectural bad smells" "architecture smells"
"anti-patterns" "architecturally-relevant code smells"
"contra-indicated patterns" "architectural defects"
"[accidental] architectural anti-patterns"
Related work
"high-impact refactorings" "architecture transformation"
"large refactorings" "architecture-oriented refactorings"
Related work
• Catalog architecture smells or refactorings • Architecture smell catalog by Garcia et al. • Catalog of smells and refactoring by M. Stal (2007)
• Specific categories of architecture smells • Ouni et al. “web service antipatterns" in the context of Service Oriented Architectures
• Rama et al. discusses “modularity smells”
Related work
•Architecture refactoring case studies performed on industrial projects
• Exploratory studies on emerging topics in architecture refactoring
• Architecture refactoring in software product lines • Architecture technical debt
• …
Potential Research Directions
Catalog of architecture smells and refactoring
Tool support
Economics of architecture refactoring (quantifying
architecture technical debt)
Refactoring and emerging architecture styles
and patterns
Example: Lack of tool support
Unlike code refactoring, most architectural refactoring is manual
due to lack of tool support!
Automated code smell detection and refactoring
[email protected] @GSamarthyam
www.codeops.tech slideshare.net/sgganesh
+91 98801 64463 bit.ly/ganeshsg