This document discusses investigating the change-proneness of service patterns and antipatterns in service-based systems. It aims to determine the relationship between various service patterns/antipatterns and change-proneness, defined as the frequency and size of changes to service source files. The study analyzes the FraSCAti OW2 system, detecting patterns/antipatterns using SODOP and SODA tools. It examines commit histories to measure changes and aims to understand how patterns/antipatterns impact maintenance effort and costs.

1. Investigating the Change-proneness of
Service Patterns and Antipatterns
Francis Palma, Le An, Foutse Khomh, Naouel Moha, and Yann-Gaël Guéhéneuc
École Polytechnique de Montréal, Canada
SOCA 2014, Matsue, Japan

2. Problem Context (1/3)
Service-based Systems
2 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
SOAP
Web Services
SCA Systems

3. Problem Context (1/3)
SOAP
Web Services
SCA Systems
Service-based Systems
Design Patterns
2 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

4. Problem Context (1/3)
SOAP
Web Services
SCA Systems
Service-based Systems
Maintenance
Evolution
SOAP Web Services
SCA Systems
Design Patterns
2 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

5. Problem Context (1/3)
SOAP
Web Services
SCA Systems
Service-based Systems
Maintenance
Evolution
SOAP Web Services
SCA Systems
- may degrade the design
- may degrade the QoS = Antipatterns
Design Patterns
2 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

6. Problem Context (1/3)
2 of 21
1. Highly change-prone?
2. Require more maintenance
efforts or cause expensive
maintenance?
SOAP Web Services
SCA Systems
Existing
Antipatterns
?
Investigating the Change-proneness of Service Patterns and Antipatterns

7. Problem Context (2/3):
Service Antipatterns and Patterns
3 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
Multi Service Antipattern

8. Problem Context (2/3):
Service Antipatterns and Patterns
Multi Service Antipattern
Proxy Service Pattern
Proxy
Service
Actual
Service
Calls Calls
Client
3 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

9. Problem Context (3/3): Detection vs. Impact
4 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
• Detection of service patterns? (SODOP, Demange et al. 2013)
• Detection of service antipatterns? (SODA, Moha et al. 2012)
• Improve/degrade the design and the QoS?
• Facilitate/hinder the maintenance and evolution of an SBS?
- impact on the change-proneness, i.e., maintenance cost?

10. Problem Context (3/3): Detection vs. Impact
Change-proneness of a service*
- number of changes
 the frequency of changes on a service source files
- code churns
 the size of changes on a service source files
4 of 21
• Detection of service patterns? (SODOP, Demange et al. 2013)
• Detection of service antipatterns? (SODA, Moha et al. 2012)
• Improve/degrade the design and the QoS?
• Facilitate/hinder the maintenance and evolution of an SBS?
- impact on the change-proneness, i.e., maintenance cost?
*Code Churn: A Measure for Estimating the Impact of Code Change: Sebastian G. Elbaum and John C.
Munson (1998)

11. Research Questions
• RQ1: What is the relation between service patterns and
change-proneness?
• RQ2: What is the relation between service antipatterns and
change-proneness?
• RQ3: What is the relation between particular kinds of service
antipatterns and change-proneness?
• Confounding impact of OO code-level smells
5 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

12. Outline
- Analysed System: FraSCAti OW2
- Study Design
- Case Study Results
- Conclusion and Future Work

13. Outline
- Analysed System: FraSCAti OW2
- Study Design
- Case Study Results
- Conclusion and Future Work

14. FraSCAti OW2
frascati.ow2.org
Investigating the Change-proneness of Service Patterns and Antipatterns
Total Services 130 (62 analysed)
Total Size 170 KLOC
Total Changed Files 15,863*
Total Java Source Files 9,020*
Total Changes 71,151*
Total Code Churns 62,676,363*
6 of 21
*Entire commit history

15. Outline
- Analysed System: FraSCAti OW2
- Study Design
- Case Study Results
- Conclusion and Future Work

16. Study Design
7 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

17. Study Design
7 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

18. Study Design: FraSCAti Commit
[[frascati-commits]] [1196] trunk/tinfi: More refactoring.
 Subject: [[frascati-commits]] [1196] trunk/tinfi: More refactoring.
 From: Lionel.Seinturier@xxxxxxx
 Date: Sat, 13 Dec 2008 21:41:32 +0100 (CET)
 Delivered-to: frascati-commits@xxxxxxx
Title: [1196] trunk/tinfi: More refactoring.
Revision
1196
Author
seintur
Date
2008-12-13 21:41:32 +0100 (Sat, 13 Dec 2008)
Log Message
More refactoring.
Modified Paths
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java
Added Paths
 trunk/tinfi/opt/comp/src/main/java/org/ow2/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCodeGenerator.java
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/InitializerCompCtrlSourceCodeGenerator.java
Removed Paths
 trunk/tinfi/opt/comp/src/main/java/org/scorware/
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/scorware/
Property Changed
 trunk/tinfi/tinfi-mixed/
Diff
Copied:
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCodeGenerator.j
ava (from rev 1186,
trunk/tinfi/opt/comp/src/main/java/org/scorware/tinfi/juliac/FCCompCtrlSourceCodeGenerator.jav
a) (0 => 1196)
---
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCode
Generator.java (rev 0)
+++
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCode
Generator.java 2008-12-13 20:41:32 UTC (rev 1196)
@@ -0,0 +1,167 @@
+package org.ow2.frascati.tinfi.juliac;
+
+import java.io.IOException;
+
+import org.objectweb.fractal.api.control.AttributeController;
+import org.objectweb.fractal.api.type.InterfaceType;
+import org.objectweb.fractal.julia.control.attribute.CloneableAttributeController;
+import org.objectweb.fractal.julia.type.BasicInterfaceType;
+import org.objectweb.fractal.juliac.InitializerClassGenerator;
+import org.objectweb.fractal.juliac.Juliac;
+import org.objectweb.fractal.juliac.JuliacConfig;
+import org.objectweb.fractal.juliac.proxy.AttributeControllerClassGenerator;
+import org.objectweb.fractal.juliac.proxy.InterfaceImplementationClassGenerator;
+import org.objectweb.fractal.juliac.proxy.ProxyClassGenerator;
+import org.objectweb.fractal.juliac.ucf.UnifiedClass;
+import org.osoa.sca.annotations.Callback;
+
+/**
+public class FCCompCtrlSourceCodeGenerator
+extends org.objectweb.fractal.juliac.opt.comp.FCCompCtrlSourceCodeGenerator {
+
+ public FCCompCtrlSourceCodeGenerator() {
+ super();
+ }
+
+
+ // -----------------------------------------------------------------------
+ // Implementation of the OptLevelSourceCodeGenerator interface
+ // -----------------------------------------------------------------------
+
....
....
....
Modified: trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java (1195 => 1196)
--- trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
2008-12-12 18:10:44 UTC (rev 1195)
+++ trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
2008-12-13 20:41:32 UTC (rev 1196)
@@ -21,7 +21,7 @@
* Author: Lionel Seinturier
*/
+package org.ow2.frascati.tinfi;
import org.objectweb.fractal.api.Component;
import org.objectweb.fractal.api.Type;
Modified: trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java (1195 => 1196)
--- trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java 2008-12-
12 18:10:44 UTC (rev 1195)
+++ trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java 2008-12-
13 20:41:32 UTC (rev 1196)
@@ -21,7 +21,7 @@
* Author: Lionel Seinturier

19. Study Design: FraSCAti Commit
[[frascati-commits]] [1196] trunk/tinfi: More refactoring.
 Subject: [[frascati-commits]] [1196] trunk/tinfi: More refactoring.
 From: Lionel.Seinturier@xxxxxxx
 Date: Sat, 13 Dec 2008 21:41:32 +0100 (CET)
 Delivered-to: frascati-commits@xxxxxxx
Title: [1196] trunk/tinfi: More refactoring.
Revision
1196
Author
seintur
Date
2008-12-13 21:41:32 +0100 (Sat, 13 Dec 2008)
Log Message
More refactoring.
Modified Paths
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java
Added Paths
 trunk/tinfi/opt/comp/src/main/java/org/ow2/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCodeGenerator.java
 trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/InitializerCompCtrlSourceCodeGenerator.java
Removed Paths
 trunk/tinfi/opt/comp/src/main/java/org/scorware/
 trunk/tinfi/runtime/oo-dyn/src/main/java/org/scorware/
Property Changed
 trunk/tinfi/tinfi-mixed/
Diff
Copied:
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCodeGenerator.j
ava (from rev 1186,
trunk/tinfi/opt/comp/src/main/java/org/scorware/tinfi/juliac/FCCompCtrlSourceCodeGenerator.jav
a) (0 => 1196)
---
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCode
Generator.java (rev 0)
+++
trunk/tinfi/opt/comp/src/main/java/org/ow2/frascati/tinfi/juliac/FCCompCtrlSourceCode
Generator.java 2008-12-13 20:41:32 UTC (rev 1196)
@@ -0,0 +1,167 @@
+package org.ow2.frascati.tinfi.juliac;
+
+import java.io.IOException;
+
+import org.objectweb.fractal.api.control.AttributeController;
+import org.objectweb.fractal.api.type.InterfaceType;
+import org.objectweb.fractal.julia.control.attribute.CloneableAttributeController;
+import org.objectweb.fractal.julia.type.BasicInterfaceType;
+import org.objectweb.fractal.juliac.InitializerClassGenerator;
+import org.objectweb.fractal.juliac.Juliac;
+import org.objectweb.fractal.juliac.JuliacConfig;
+import org.objectweb.fractal.juliac.proxy.AttributeControllerClassGenerator;
+import org.objectweb.fractal.juliac.proxy.InterfaceImplementationClassGenerator;
+import org.objectweb.fractal.juliac.proxy.ProxyClassGenerator;
+import org.objectweb.fractal.juliac.ucf.UnifiedClass;
+import org.osoa.sca.annotations.Callback;
+
+/**
+public class FCCompCtrlSourceCodeGenerator
+extends org.objectweb.fractal.juliac.opt.comp.FCCompCtrlSourceCodeGenerator {
+
+ public FCCompCtrlSourceCodeGenerator() {
+ super();
+ }
+
+
+ // -----------------------------------------------------------------------
+ // Implementation of the OptLevelSourceCodeGenerator interface
+ // -----------------------------------------------------------------------
+
....
....
....
Modified: trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java (1195 => 1196)
--- trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
2008-12-12 18:10:44 UTC (rev 1195)
+++ trunk/tinfi/runtime/oo-dyn/src/main/java/org/ow2/frascati/tinfi/Tinfi.java
2008-12-13 20:41:32 UTC (rev 1196)
@@ -21,7 +21,7 @@
* Author: Lionel Seinturier
*/
+package org.ow2.frascati.tinfi;
import org.objectweb.fractal.api.Component;
import org.objectweb.fractal.api.Type;
Modified: trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java (1195 => 1196)
--- trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java 2008-12-
12 18:10:44 UTC (rev 1195)
+++ trunk/tinfi/runtime/oo-
dyn/src/main/java/org/ow2/frascati/tinfi/TinfiBootstrapComponentImpl.java 2008-12-
13 20:41:32 UTC (rev 1196)
@@ -21,7 +21,7 @@
* Author: Lionel Seinturier

20. Study Design
7 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

21. Study Design
7 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

22. Study Design
 Detection of Service Patterns:
SODOP – Service Oriented Detection Of Patterns (Demange et al. 2013)
 Detection of Service Antipatterns:
SODA – Service Oriented Detection for Antipatterns (Moha et al. 2012)
8 of 21
Names Detected
Instances
Involved Java
Source Files
Patterns
Adapter 1 14
Basic Service 5 54
Facade 3 62
Proxy 3 61
Antipatterns
Bloated Service 3 25
Bottleneck Service 2 24
God Component 2 4
Multi Service 1 5
Nobody Home 4 12
Service Chain 3 10
The Knot 1 24
Tiny Service 1 24
OO Code Smells - 26,381 3,717

23. Study Design
9 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

24. Study Design: Variables
 Independent Variables
Eight service antipatterns and four service patterns
i. f1
i  a file i was involved in the implementation of at least one pattern (RQ1)
ii. f2
i  a file i was involved in the implementation of at least one antipattern (RQ2)
iii. f3
i,j  a file i was involved in the implementation of antipattern j (RQ3)
 Dependent Variables
Change-proneness of services' source files
i. total number of changes as ci
ii. total number of code churns as di
10 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

25. Study Design: Interpretation of Values
 Interpreting the effect sizes
 Interpreting the p-values
11 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

26. Outline
- Analysed System: FraSCAti OW2
- Study Design
- Case Study Results
- Conclusion and Future Work

27. RQ1: What is the relation between service patterns
and change-proneness?
12 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

28. RQ1: What is the relation between service patterns
and change-proneness?
12 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
H1
01 : there is no difference between the total number of changes experienced
by files involved in the implementation of a service pattern and other files
H2
01 : there is no difference between the total number of code churns
experienced by files involved in the implementation of a service pattern and
other files

29. H1
01 : there is no difference between the total number of changes experienced
by files involved in the implementation of a service pattern and other files
H2
01 : there is no difference between the total number of code churns
experienced by files involved in the implementation of a service pattern and
other files
12 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
RQ1: What is the relation between service patterns
and change-proneness?
SODOP
Measure
change-proneness
Test H1
01 &H2
01
(Wilcoxon rank sum test)

30. Findings RQ1: Patterns are less change-prone but
not at (statistically) significant level
13 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

31. 13 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
Findings RQ1: Patterns are less change-prone but
not at (statistically) significant level

32. 13 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
Findings RQ1: Patterns are less change-prone but
not at (statistically) significant level

33. RQ2: What is the relation between service
antipatterns and change-proneness?
14 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

34. RQ2: What is the relation between service
antipatterns and change-proneness?
14 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
H1
02: there is no difference between the total number of changes experienced
by files involved in the implementation of a service antipattern and other files
H2
02 : there is no difference between the total number of code churns
experienced by files involved in the implementation of a service antipattern and
other files

35. 14 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
RQ2: What is the relation between service
antipatterns and change-proneness?
H1
02: there is no difference between the total number of changes experienced
by files involved in the implementation of a service antipattern and other files
H2
02 : there is no difference between the total number of code churns
experienced by files involved in the implementation of a service antipattern and
other files
SODA
Measure
change-proneness
Test H1
02 & H2
02
(Wilcoxon rank sum test)

36. Findings RQ2: Antipatterns are more change-prone
at the statistically significant level
15 of 21

37. 15 of 21
Findings RQ2: Antipatterns are more change-prone
at the statistically significant level

38. RQ3: What is the relation between particular kinds
of service antipatterns and change-proneness?
16 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

39. RQ3: What is the relation between particular kinds
of service antipatterns and change-proneness?
16 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
H1
03: there is no difference between the total number of changes experienced
by files from groups (GAi)iє{1,….8} and GNoAP
H1
03: there is no difference between the total number of code churns
experienced by files from groups (GAi)iє{1,….8} and GNoAP

40. H1
03: there is no difference between the total number of changes experienced
by files from groups (GAi)iє{1,….8} and GNoAP
H1
03: there is no difference between the total number of code churns
experienced by files from groups (GAi)iє{1,….8} and GNoAP
16 of 21
RQ3: What is the relation between particular kinds
of service antipatterns and change-proneness?
SODA
Measure
change-proneness
Test H1
03 & H2
03
(Kruskal-Wallis test)
Classify source files
(antipatterns vs non-antipatterns)

41. Findings RQ3: Antipatterns (investigated in this
study) are not equally change-prone
17 of 21

42. 17 of 21
Findings RQ3: Antipatterns (investigated in this
study) are not equally change-prone

43. Confounding Impact:
Are service antipatterns more vulnerable to OO
code-level smells (and vice-versa for service pattern)?
18 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

44. Confounding Impact:
Are service antipatterns more vulnerable to OO
code-level smells (and vice-versa for service pattern)?
18 of 21Investigating the Change-proneness of Service Patterns and Antipatterns
SODA
SODOP
Compare the groups
(Wilcoxon rank sum test)
Classify source files
(patterns vs. non-patterns)
(antipatterns vs. non-antipatterns)

45. Findings on Confounding Impact
19 of 21
 Service antipatterns contain more (but not statistically significant) code smells
 Service patterns contain less code smells at the statistically significant level

46. Findings on Confounding Impact
19 of 21
 Service antipatterns contain more (but not statistically significant) code smells
 Service patterns contain less code smells at the statistically significant level

47. Take Home Message…
• Developers should avoid implementing Service
Antipatterns to
- reduce maintenance efforts and costs, and
- improve maintainability and ease evolution
• Implemented service patterns have less code-level
OO smells
20 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

48. Outline
- Analysed System: FraSCAti OW2
- Study Design
- Case Study Results
- Conclusion and Future Work

49. Conclusion
21 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

50. Conclusion
21 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

51. Conclusion
21 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

52. Conclusion
21 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

53. Future Work
• Future works include
- replicate the study on other SBSs and service antipatterns
- investigate the changes types and their impact on antipatterns
- investigate the relation between service antipatterns
and fault-proneness
21 of 21Investigating the Change-proneness of Service Patterns and Antipatterns

54. Questions ?