The document discusses migrating an existing online infrastructure to a new service-oriented architecture using Mule as an ESB. The existing infrastructure was complex and expensive to maintain. The goals of the new architecture were to simplify operations, standardize backend access, and reduce costs. Mule was selected as the ESB after evaluating options based on criteria like support, performance, and developer experience. Examples of how Mule is used include exposing a unified web service interface, adapting legacy services, and building a scalable clustered deployment. Best practices discussed include testing with functional tests and mocks, and migrating the architecture in staged phases.

1. Service-Oriented Online Architecture with Mule
A different approach to building a SOA

2. Agenda
• 1. Business context and problems faced
2.The idea of a service-oriented online
architecture
3.How and why we selected Mule
4.Overview and examples of Mule use cases
5.Best practices and learnings
2

3. Business context and problems faced
Existing online infrastructure was
complex, expensive
to maintain and could not be used
by other portals
3
Corporate Network
(Head Quarter)
Portal
Distribution DMZ
Partner LAN
(*) as Reverse Proxy
 Business logic and backend access in the portal needs to available to other portals
 Server applications only run on specialized hardware and application platform
 Everyone is talking to everyone, point-to-point communication is difficult to manage
Web-
Server (*)
Web-
Server (*)
Browser Oracle
DB2
BackendBackend
BackendBackend
Client-
Application
Client-
Application
Data
Platform
Component
Application
Platform
Online-
ServerServer-
Application
Server-
Application
- Spare Parts
- Technical Info
- …

4. An ESB-centric service-oriented
online architecture is
easier to manage and more
extensible
4
Business context and problems faced
Online
Client
Corporate Network
(Head Quarter)
DMZ
Primary
ESB
Backend
Portal
Online-
Server
(*) as Reverse Proxy
Local Area Network
Web-
Server (*)
Web-
Server (*)
Browser

5. ■ The migration of the server applications to standardized
hardware proved to be rather difficult due to close coupling to
platform
■ To get rid of the application platform components we had to
identify the all required services for the online scenario
■ Then a light-weight surrogate based on Mule was implemented
to provide these services to the applications instead
■ The portal independent services had to be identified and
extracted from the portal
■ Access to all backend systems is now provided by one central
Mule ESB instance, implementing logging and security
■ The maintenance costs for the simplified architecture have
already decreased significantly
■ New server application instances can be deploy transparently
within hours instead of days now
Business context and problems faced
The goal was to simplify the
architecture, unify the way
backend systems are accessed and
cut operation costs
5

6. Agenda
• 1. Business context and problems faced
• 2. The idea of a service-oriented online
architecture
3.How and why we selected Mule
4.Overview and examples of Mule use cases
5.Best practices and learnings
6

7. The improved service-oriented
online architecture can be
composed using different building
blocks
7
The idea of a service-oriented online architecture
Online
Client
Corporate Network
(Head Quarter)
DMZ
Primary
ESB
Backend
Portal
Online-
Server
(*) as Reverse Proxy
Local Area Network
Web-
Server (*)
Web-
Server (*)
Web-
Server (*)
Local
ESB
Browser

8. A secondary ESB building block
enables the deployment
of dedicated online servers in
national networks
8
The idea of a service-oriented online architecture
Local
ESB
Corporate Network
(Head Quarter)
Primary
ESB
Backend
Portal
Online-
Server
National Corporate
Network (USA)
Secondary
ESB
DMZ
Backend‘
Local Area
Network
(*) as Reverse Proxy
Web-
Server (*)
Web-
Server (*)
Web-
Server (*)
Browser
Online-
Client

9. Multiple portal and online server
blocks can be combined
to support different user groups
and network locations
9
The idea of a service-oriented online architecture
Corporate Network
Primary
ESB
Backend
Portal
Online-
Server
National Corporate
Network (USA)
Secondary
ESB
DMZ
Backend‘
Local Area
Network
Web-
Server (*)
Web-
Server(*)
(*) as Reverse Proxy
Local
ESB
Browser
Online-
Client
Web-
Server(*)
Portal
Online-
Server

10. Agenda
1.Business context and problems faced
2.The idea of a service-oriented online
architecture
• 3. How and why we selected Mule
4.Overview and examples of Mule use cases
5.Best practices and learnings
10

11. ■ We did not Google „open source ESB“ to select Mule …
■ Instead we did a qualitative and quantitative comparison of major open source ESB
products using different criteria:
■ Primary: professional maintenance, commercial support with SLAs, licensing, performance,
operations by IT department possible
■ Secondary: documentation, code quality, activity and size of community, Spring support, sync
and async communication, supported standards, app server integration, development tools
■ Mule quickly emerged as the favored ESB product, followed by Fuse ESB and WSO2
■ Static analysis of the Mule sources (Sonar,
Structure101) showed acceptable quality
■ Modularization and project structure looks well-
thought-out and enables light-weight deployment
■ Good code quality, in spite of found violations and
partially low documentation
■ Test coverage is reasonably high to ensure correct
function in case of changes
How and why we selected Mule
Based on the proposed architecture
scenarios we could
identify the requirements on the
ESB product
11

12. ■ Chosen products: Mule ESB, WSO2
and Fuse ESB
■ Are all 3 uses cases supported?
■ Development model: used frameworks,
supported IDEs, build tools?
■ Learning curve: How good is the
documentation? ClearAPI?
■ Development effort: How long does it
take to implement the uses cases?
■ Mule ESB scored best in comparison,
closely followed by WSO2
How and why we selected Mule
Implementation of a small PoC
prototype to get a first
impression of the chosen products
121 2 3WS-Call  POJO Provider External WS-Call (Asnyc) WS-Proxy with Transform

13. ■ Different load scenarios with constant and
increasing parallel requests (Apache JMeter)
■ Measurement of performance relevant
metrics using Software-EKG
■ Live profiling of system behavior (JProfiler)
■ All findings have been reported to MuleSoft
■ Together with MuleSoft we were able to solve
all the found issues:
■ MuleSoft supplied a working patch for the
Registry synchronization issue within 2 days
■ Other issues could simply be addressed using
the optimized configuration parameters (thread
pool settings, …) supplied to us
■ This was decisive for the confidence and the
final decision for Mule ESB
How and why we selected Mule
Intensive performance tests
uncovered several findings
(with Mule 3.1.1) …
13

14. Agenda
1.Business context and problems faced
2.The idea of a service-oriented online
architecture
3.How and why we selected Mule
• 4. Overview and examples of Mule use
cases
• 5. Best practices and learnings
14

15. Clustered deployment of Mule ESB
as a web application
for scalability and high availability■Requirement: Mule
ESB had to be
deployed as a Java
web application to be
operated by the IT
department
■Embedding Mule into
a web app is pretty
• straight forward using
the a context listener 15
Overview and examples of Mule use cases

16. Overview and examples of Mule use cases
Unified web service interface to
access details user
from heterogeneous data sources
16
■ Access to the endpoint is controlled
using a Spring security filter
■ Each data source has specific POJO
implementation or private flow
■ Choice is based on payload using a
Groovy evaluator

17. ■ Only minor Java code required
■ Web service interface and types
■ Custom transformers
■ Choice uses CXF operation header
■ XSLT to transform XML/RPC to
JAXB XML structure
Overview and examples of Mule use cases
Web service to XML/RPC service
adapter to access the
BZST service for simple and
qualified VAT checks
17

18. ■ Web service interface and types defined as
POJI and POJOs with JAX-WS annotations
■ The service component only performs
validation and preprocessing of request
Overview and examples of Mule use cases
Web service to email service
adapter to send support
requests to a ticketing backend
system
18
■ The actual sending using an SMTP
connector is performed asynchronous
■ Custom transformer uses Velocity to
convert request object to email body

19. Agenda
1.Business context and problems faced
2.The idea of a service-oriented online
architecture
3.How and why we selected Mule
4.Overview and examples of Mule use cases
• 5. Best practices and learnings
19

20. ■ Mule provides several built-in components
to test Mule XML and flow definitions
■ The MuleFunctionalTest allowed us to test
our flows within the IDE
■ No deployment to a standalone instance
required, thus reducing turn-around times
■ The MuleClient is not really intuitive to use
■ Smart combination of SoapUI test cases
together with mock services allowed 100%
local and off-site development
■ Learning: develop as much as possible as
POJOs and use „traditional“ unit testing
■ Learning: take the time to write a good
mock for the service you are integrating
Best practices and learnings
Test driven development using
MuleFunctionalTests,
SoapUI tests and mock services
20

21. ■ „The Leanest, Meanest ESB: Mule ESB is the world's most efficient Enterprise
Service Bus” (http://www.mulesoft.com/mule-esb-small-footprint)
■ We went well below the mentioned figures by building a custom Mule distribution
tuned and optimized for our specific use cases
■ Based on the default distribution assembly XML found in the Mule community
sources, we
1. got rid of everything not required in production, mainly docs and examples, but also not
required Tanuki EXE wrapper binaries, etc.pp.;
2. selected only the required Mule modules and transports our uses cases really required, this
reduced the amount of 3rd party libs significantly;
3. used Maven dependency management to have full control of all used 3rd party libraries,
used more recent versions where possible (e.g. Spring, CXF, Saxon)
4. added our Mule apps and their dependencies, then repackaged
■ Thorough load tests lead to optimized JVM parameters and high performance:
-Xmx=128m -Xms=128m -XX:MaxPermSize=64m -XX:NewRatio=2 -XX:SurvivorRatio=12 -XX:+UseParallelGC
-XX:+UseParallelOldGC
Best practices and learnings
Building a custom Mule distribution
for 100% control of
all dependencies and optimal
performance
21
96 MB
30 MB
37 MB

22. ■ A migration of the whole infrastructure in one go would
have been impossible; the system needs to be
available around the clock
■ Instead a staged migration of the infrastructure
components and applications has been used:
■ Phase 1: Migration of all online servers, application by
application, introduction of the primary ESB with first
required services
■ Phase 2: Integration of a new online portal, operated in
parallel to the old portal infrastructure
■ Phase 3: Migration of all „legacy“ portals to access the new
online infrastructure components
■ After each phase the behavior of the new components
was monitored closely to detect any problems in
production
■ The services and backend systems integrated by the
primary ESB instance constantly grew (I might still be
growing in next phases)
Best practices and learnings
No big bang: start small and migrate
in several phases
22

23. Questions & Answers