1. C++ In SOA
Nandika Jayawardana
Tech Lead, WSO2, Inc
nandika@wso2.com

2. Introduction to SOA in C++
● In this presentation we will look in to the
implementation of SOA using Web Services in
the C/C++ world from a native Web Services
Stack's point of View.

3. Why use C++
● C++ is still widely used in the industry due to
● Performance advantage of the native code
● Flexibility available from object oriented
language
● Tight control over memory and CPU

4. Typical applications that use
C++
● Applications which require high performance
and the ability to handle large volumes of
data
● Financial Market Applications
● Large E-Commerce applications
● Banking Applications
● Telecommunication Systems
● Data Base Systems
● Applications which require tight control over
memory and CPU
● Operating Systems (C/C++)
● Embedded Systems

5. Some Use cases
● A legacy C++ system which has been performing
useful work for a long time. This has remained
isolated while all other systems in the
organization evolved and connected together.
● Need to integrate this system with other
applications to use its functionality in a broader
perspective.
● Options
● Rewrite the system ( Costly )
● Integrate using EAI
● Integrate using a native Web Services Stack

6. Some Use Cases
SAP
.NET
Legacy
System Secure, Reliable, Binary
J2EE
Web Services
CICS
Java

7. Some Use cases
● A high performance application is used in an
organization (Telecommunication, Banking )
● Need to provide new products and services
using the system on a regular basis to keep up
with market competition
● Difficult to keep changing, adding new
functionality to the existing system
● Does a better way exist to cater for the new
requirements without the hassle of change or
loosing the performance ?

8. Some Use cases
● I need my embedded system (camera, car,
printer, robot, ... ) to be able to talk to
external systems which are running
heterogeneous hardware and software

9. SOA
● Decomposing business function into
reusable, independent components which
communicate using standard protocols with
messages and semantics defined by
contracts.
● SOA is an Enterprise Architecture
● The application using a service should be
independent of the location and
implementation of any services it uses

10. SOA

11. Why SOA
● SOA simplifies connecting systems
● Integration is driven by number of factors
● Straight-through-processing
● Handling web transactions without manual
intervention, leading to greater scalability
● Mergers and De-mergers
● The increasing change in organizational structure is
making loosely-coupled connections more important
● Partnerships
● Outsourcing
● Time to Value

12. Native Web Services Stack
● What would you look from a native web
services stack to solve the above stated
problems ?
● Support for Basic Web Services Standards
● Tooling for WSDL
● Portability
● Performance / Low memory foot print
● Security
● Ability to handle binary data
● Interoperability
● Asynchronous communication

13. Basic Web Service Standards
● SOAP 1.1 , 1.2
● WSDL (Web Services Description Language)
● XML Schema
● HTTP
<soap:Envelope
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header/>
<soap:Body>
<getProductDetails
xmlns="http://warehouse.example.com/ws">
<productID>827635</productID> </getProductDetails>
</soap:Body>
</soap:Envelope>

14. Working with WSDL
● WSDL (Web Service Description Language)
● defines a service contract
● Focuses on:
● What the messages are
● Schema
● How they flow (in, in-out, etc)
● Message Exchange Pattern
● Where they are
● Endpoint URLs

15. Working with WSDL
● WSDL is complex
● WSDL is intended to be machine readable
and machine processable
● Typical approaches to building services and
clients using WSDL
● Code Generation ( Common)
● Dynamic Invocation ( Rare )

16. Code Generation
Stub
<wsdl/>
Code Generation Tool
document
Skeleton

17. Advantages of Code Generation
● All complex details of mappings between
C++ types and XML schema types are handled
by the generated code.
● The developer deals with C++ types
● Quickly develop services and clients
● Faster than the dynamic invocation technique
● Developer can concentrate on his business
logic

18. Working with WSDL in WSF/C++
● Comes with built in Code Generation tool.
● Generates Client Stubs, Service Skeletons,
Service descriptors and Build scripts.
● Generating a Service Skeleton
Linux: sh WSDL2CPP.sh -uri calculator.wsdl -ss -sd -d adb -u
Windows: WSDL2CPP.bat -uri calculator.wsdl -ss -sd -d adb -u
● Generating a Client Stub
Linux: sh WSDL2CPP.sh -uri calculator.wsdl -d adb -u
Windows WSDL2CPP.bat -uri calculator.wsdl -d adb -u

19. How to adapt a C++ Application
as Web Services

20. Using WSF/C++
● Supports multiple platforms
● Linux
● Windows
● Solaris

21. Portability
● My legacy application is running on platform
'X'. Does your Web Service stack run on it ?
● It can boil down to multitude of issues
● Differences in operating system versions
● Differences in build tool versions, compiler
versions
● Dependency problems

22. Performance
● Performance is a broad area. Usually
Performance means response time. In another
way, how many requests can the server
handle per second
● However, performance depends on the
system's hardware as well as load on the
system
● Does the performance stay constant or does it
degrade over time
● How does the performance vary with the size
of the messages, load of the system

23. Low Memory Foot Print
● Some servers take large amount of memory
just to start up
● How much memory does it require to run
efficiently ( Important in embedded systems)
● Does the memory usage stay constant while
handling large xml messages, large binary
content

24. Security
● Important, confidential data need to be
exchanged between parties.
● Transport Level security
● Message Level Security

25. Security Terminology
● Confidentiality
● The assurance that the message has not been read
by anyone other than the intended reader
● Integrity
● The assurance that data is complete and accurate
● Non-repudiation
● Prevent denial of action
● unforgeable evidence
● Authentication
● The verification of a claimed identity

26. Transport Level Security
● Achieved by using HTTPS
● Provides confidentiality through encryption
● Provides integrity through digital signature
● Service authenticate to client via certificates
● Client can authenticate to the service via
certificates / basic, digest authentication

27. Transport Level Security
HTTPS
Client Service
Is it really what you want ?

28. Transport Level Security vs
Message Level Security

29. Message Level Security
● Achieved using WS-Security
● Authentication with UsernameToken
● Provides confidentiality through encryption
● Provides integrity and non-repudiation
through digital signature

30. Security with WSF/C++
● Supports Both transport Level security and
Message Level Security
● Security is configured using WS-Security
Policy
● Client is configured by specifying the policy
configuration.
● Service is configured for security by the
deployment script
● Eg
ServiceClient sc(client_repo, end_point);
sc.engageModule(“rampart”);
sc.setPolicy(new NeethiPolicy(security_policy_file));

31. Handling binary data
● “Attachments”
● Video, Images, Documents, ...
● There are two ways to transfer binary data in
SOAP
● By Value (Encoded text of data within the xml)
● base64 – 4/3x original size
● hex – 2x original size
● Reference
● pointer to outside the XML
● MTOM/XOP
● Standardised approach to transfer binary data

32. Attachment handling with
WSF/C++
● Supports
● Base64
● MTOM and SwA
● Support for caching large attachments
● Class DataHandler which handles binary content
// Enable mtom in the options object.
options->setEnableMTOM(true);
// Create a Data Handler with the image
OMDataHandler * data_handler = new
OMDataHandler(image_file_name, "image/jpeg");
// Create OMText with Data Handler
OMText * child3 = new OMText(child2, data_handler);

33. Interoperability
● The ability of two or more systems or
components to exchange information and to
use the information that has been exchanged
● Achieved by adherence to the specifications
and regular testing against other systems
● Interoperability with the major SOA players
guarantees that you services will be accessible
by other products and your clients will be
able to talk to other services

34. WSF/C++ and Interoperability
● Interoperability tested with .Net, Axis2 and
other Java Web Services Stacks
● Has been tested with data types (Complex,
Simple) as well as advanced features such as
XOP/MTOM, WS-Security, WS-RM

35. WSF/C++
● SOAP 1.1 and SOAP 1.2
● WS-Addressing
● 1.0
● submission
● MTOM and SwA
● Support for caching large attachments
● WS-Security
● Base security standards mean that messages can be
protected using Encryption, Authentication and Signature
● Including WS-SecureConversation and WS-Trust
● WSDL2CPP Code Generation tool
● Supports generating client stubs, service skeletons, build
scripts and deployment scripts

36. WSF/C++
● WS-Policy and WS-Security Policy
● Enables using industry standard XML to configure security
● SSL Enabled Transport Layer
● WS-Reliable Messaging 1.0, 1.1 and WS-RMPolicy
● Enables reliability between platforms including message resending, duplicate
detection and persistence
● Full REST support (GET, PUT, DELETE, POST)
with custom URI Mapping
● Enables mapping a REST API easily and naturally
● Useful tools
● Tcpmon
● wsclient

37. Q&A