PowerPoint PresentationIndia SAP CoE, Slide *
ESB (Enterprise Service Bus)
Fundamentals: An enterprise service bus (ESB) is a software architecture for middleware that provides fundamental services for more complex architectures.
That leads us to the question:
What all does the ESB incorporate?
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ESB Contd……
Structural representation:
These are the various parts of the ESB. Routing, Load Balancing, Transformation, Message Validation and security.
India SAP CoE, Slide *
ESB Introduction
ESB is positioned typically as a “middle ware application, where it acts as a buffer layer for services exposed across a heterogeneous applications
An ESB provides
combines messaging, web services, protocol & data transformation, and intelligent routing
enables a highly distributed, loosely coupled event driven SOA in a heterogeneous environment
scales to support global deployment, and
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Structured according to harmonized enterprise model based on process component, business object and Global Data Types.
Quality and stability:
Standards:
India SAP CoE, Slide *
India SAP CoE, Slide *
ESB Introduction Continued….
In a Central landscape all messages and data flow through a central system – a Broker , an ESB or a Gateway. This provides Central Governance, Security etc.
What all does the ESB provide?
it provide s us advanced tools to map data structures and controls from one system to the other
it provides a standard abstraction; using the same skill set we can map different systems
it provides us tools to implement security , governance ,monitoring
it provides us options to manifest changes in the landscape with the help of configurations
India SAP CoE, Slide *
Integration
One of the primary features of ESB is its support for Services (especially Web Services).
ESB Exposes the abstract endpoint of the registered integrated service so that service is consumed by sending a message to the ESB endpoint                   
 Uses the awareness of interface, protocol and data format and uses internal Service Invocation framework to translates message send/receive into a call to the underlying service.
Achieves Service Virtualization by exposing service endpointsfor discovery
Maintains an internal registryused for routing and storing service metadata
Provides Light weight service orchestration i.e. Coordinationof multiple implementation services to expose as a single, aggregate service that in turn can be used by service orchestration layer of a composite application.
Provides Error Handling - ability to capture and process faults at service, pipeline and other stages
Provides authentication and authorization features,transport and message level security, auditing of activities on services and Single sign on
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1. Protocol Transformations
Maps and transforms into appropriate protocol required by the end-point service, allowing for dynamic run-time protocol switching
India SAP CoE, Slide *
Integration
Adaptors
Use of Adapters, to enable connectivity into packaged and custom enterprise applications, as well as leading technologies. For example, Legacy , Packaged Applications, technologies such as EJB  can be made to communicate using adaptors.                                                                                                     
ESB also achieves protocol and data transformation required by the connected enterprise system
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Communication
Addressing
This mainly deals with interpreting the physical location or network address of the service.
Transportation
Bindings
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ESB routes of requests to the relevant service provider.
Provides Static Routing by looking up service endpoint in ESB Namespace Directory or Routing information table in database where the Itinerary defining which endpoint to visit is mentioned in the message
Provides Dynamic Routing by examining message content and configured rules for content based routing
Updates externalized routing directory shields the requester of any changes to the provider location
Provides Intelligent routing based on infrastructure intelligence.
It provides Synchronous & Asynchronous Message Processing,Multiple message exchange patterns (request/response, publish/subscribe, fire-and-forget) , Validation, Transformation, Enrichment and  Persistence.
India SAP CoE, Slide *
Mediation
The Contract between the requestor and provider of the service are realized by using a set of mediation modules.
ESB serves as the Service Mediation layer and enables -
Transport Protocol–Interaction with services over multiple transport protocols.    
Data Conversion–Data transformation between interacting services.              
Runtime Policy Enforcement-Point of enforcement of runtime rules (like security etc.) on interacting services.
Pipeline Processing–Application of filters and routing rules on messages that are easily configurable to facilitate service interaction.  
Loose Coupling–De-coupling of service consumer (client) and service provider, so that any changes to either of them is masked from rest of the interacting services
India SAP CoE, Slide *
Administration
Managing changes and versions of services being published
Configuring audit on message saves, edits and resubmits and maintaining the log history
Monitoring
Exception Mediation
View of the messages that raised faults through the console
Message repair options to edit the faulty message and resubmit
Alert subscription and Notifications on error for user groups
Service Levels
Provide visibility into service utilization and other service metrics like response time and faults
India SAP CoE, Slide *
XI/PI as ESB
PI/XI is able to provide the capabilities defined by an ESB up to “certain” extent. In SAP NetWeaver, the integration tool is currently Process Integration/Exchange Infrastructure which is architected much similar to an EAI broker.
ESB provides Message Oriented Middleware and above that several “generic” services, which handle the traffic and routing on the Bus:
Transformation service
XI/PI as ESB
The evolution of XI/PI is based on MOM OR Hub and spoke based EAI. ESB architecture is far ahead of this Hub and Spoke concept, its not only limited upto integrating various applications in distributed environment but also have provide an Event Driven Architecture.
India SAP CoE, Slide *
SOAMANAGER
SOA Manager to administer and configure service providers and consumer proxies for a local system.
Communication Between a Consumer Proxy and a Provider Proxy
Communication between the service consumer and the service is established between the consumer proxy’s logical port the provider proxy’s endpoint.
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Configuring a Service Provider
To configure a service provider, you need to create and configure an endpoint. The endpoint contains a runtime configuration, which is needed to implement the service.
India SAP CoE, Slide *
Configuring a Consumer Proxy
You can configure individual service consumers by applying the configuration settings for each proxy definition. To configure a consumer proxy to access a particular service, you need to create and configure one or more logical ports.
Logical Ports:
A logical port references an endpoint, which is available at a unique location on the provider system.
India SAP CoE, Slide *
Based on the WSDL document for a service.
You need to know:
The URL that points to the WSDL document for the service
The access parameters for the WSDL document
Manually
You need to know:
The configuration settings that the provider expects
India SAP CoE, Slide *
India SAP CoE, Slide *
SOAMANAGER Configuration
ABAP Server
For this service to work it we must active it on SICF
India SAP CoE, Slide *