EU projects
MODAClouds and JUNIPER –
Writing and testing
transformations from abstract
object oriented domain models
Marcos Almeida, SOFTEAM | ModelioSoft
RCIS’13
www.modeliosoft.com
1
What’s this presentation about?
• This is not a presentation about solutions but about
problems.
• Future of Internet = Platform Fragmentation
• MDE Approach =
Specific Models / code
Abstract Models
Business
Objects
Transformation
Transformation
HDFS
MySQL
Transformation
PROBLEM!!
MongoDB
Given this fragmentation:
How to write and test these
transformations?
www.modeliosoft.com
2
Context: two FP7 projects that just started…
http://www.modaclouds.eu/ - 318484
http://www.juniper-project.org/ - 318763
www.modeliosoft.com
3
What’s the “Future of Internet” for MODAClouds?
The
Cloud
The
Cloud
The
Cloud
The
Cloud
The cloud? No!
Multiple clouds,
Multiple providers,
Fragmentation!
Our mission:
• Develop applications in a cloud independent way
• Provide support for app monitoring, adaption and migration
www.modeliosoft.com
4
What’s the “Future of Internet” for JUNIPER?
• The main keyword: Big Data
o Multiple streams
o Multiple types
o Real-time constraints
• Current state of the art: NoSQL
o Pros
• Optimized for non-relational data
• Optimize query engines for performance not for expressivity
o Cons
• The code is “ the model” 
• How to deal with the different NoSQL databases?
• Our mission
o Modeling support for non relational & real-time big data application
www.modeliosoft.com
5
The main problem is FRAGMENTATION!
• Many different database management systems
o Ex:
•
•
•
•
•
MySQL (www.mysql.com/),
Big Table (http://research.google.com/archive/bigtable.html)
SimpleDB (http://aws.amazon.com/simpledb/)
Memcached (http://memcached.org/)
…
• Many underlying data representation paradigms
o Ex:
•
•
•
•
•
Relational Databases
Key-value Stores
Object-oriented Databases
Big Tables
…
www.modeliosoft.com
6
The basis of our solution is MDE… Why?
Specific Models / code
Abstract Models
Business
Objects
Transformation
HDFS
Transformation
MySQL
Transformation
MongoDB
• Separating the problem from the solution
• Fostering automation
o Analysis
o Code generation
www.modeliosoft.com
7
What do we get from MDE?
Pros
• Design data once, store
everywhere!
• Write your transformation
once, transform anything!
Cons
• Transformations are hard to
write…
• How to make sure they are
CORRECT? i.e.
– Is there any data/semantic
loss?
www.modeliosoft.com
8
Understanding the problem… Why is it so
HARD? (1/3)
• Target Technologies based on different paradigms
• Example:
JPA
@Entity
public class A {
@Basic
public B getB(){
…
}
…
}
A
B
SQL
create table A (…)
create table B (…)
create table A_B (…)
www.modeliosoft.com
9
Understanding the problem… Why is it so
HARD? (2/3)
• Target structure is variable
• Example:
Here A and B
are
independent
entities
ER
A
A
B
AB
B
NoSQL
A
Here, for
performance
reasons, B is
embedded in A
B
www.modeliosoft.com
10
Understanding the problem… Why is it so
HARD? (3/3)
• Different implementations support different features
• Example:
JPA
In JPA inheritance is usually implemented as
an extra column with a type
A
Hibernate:
ignores the
column
B
x:int
www.modeliosoft.com
y:string
Toplink:
ignores its
type
Disc(?):int(?)
11
Our experience
• Just in the beginning
• Some experiments
o Persistence Model  JPA x SQL
• Current approach:
o Decomposing transformations
o Dealing with variability by replacing sub-transformations
o Unit testing sub-transformations
• Automated Tests
– 90 JUnit Tests
• Manual Integration Test
– ~100 Tests
www.modeliosoft.com
12
Decomposing transformations
Persistence Model  JPA
Entities  Java Classes
Identifiers  Attributes
…
www.modeliosoft.com
13
Dealing with variability by replacing subtransformations
Persistence Model  JPA (JSR 317)
Persistence Model  JPA (Hibernate)
Entities  Java Classes
Entities  Java Classes
Identifiers  Attributes
Identifiers  Attributes
…
…
www.modeliosoft.com
14
Unit testing sub-transformations
Desired output
@Basic
private Integer at;
Obtained output
+ at : Integer
Input
@Basic(fetch=FetchType.LAZY)
private Integer at;
Transformation
www.modeliosoft.com
Output
15
Limitations
Tool 1
Input
Transformation
Output
Tool 2
• Actual tools do not behave exactly as expected…
o Each tool interprets the outputs in a different way
o The range of acceptable outputs may vary from a tool to another
• Integration Test Involves interfacing with complex code
o Modelio, testing databases (MySQL…), Different JPA
implementations (Hibernate Eclipse Link, TopLink…)
www.modeliosoft.com
16
Conclusion
• We focus on MDE for future of the internet applications
• But in practice… MDE needs to support to the platforms
supporting these applications…
• Limitations, Limitations, Limitations…
o Fragmentation x Integration Testing
• Problems
o Too many different targets
• How to test such transformations?
• How to interface with complex software?
• How to reduce manual work?
www.modeliosoft.com
17
Thank you for your attention!
Marcos Almeida
SOFTEAM | ModelioSoft
marcos.almeida@softeam.fr
SOFTEAM R&D Web Site:
http://rd.softeam.com
ModelioSoft Web Site:
http://www.modeliosoft.com
www.modeliosoft.com
18
M o d e l i n g s o l u t i o n s.