This commit modifies files in the FraSCAti system and contains refactoring. Specifically, it modifies two Java files, copies one Java file by changing its package, and removes two package paths. The commit log indicates it contains "More refactoring".

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 ?