SAP technology Overview (III)

ESA (Enterprise Service Architecture)

ESA (Enterprise Service Architecture)

To put it simply, ESA is a concept of SAP based on SOA (Service Oriented Architecture. The main purpose is to use WebService to further improve the uniformity and reusability between SAP Business systems. We recommend a more convenient business process development model. The main means is

Establish a service-centered development model, because the service has advantages such as low coupling, cross-Internet, wider range, cross-platform, and more flexible granularity compared with other software encapsulation technologies.

Build a unified service infrastructure (Esi) based on the Web service ).

Establish the so-called "Mode-driven" development mode. In fact, I understand that, based on the powerful service infrastructure, there is a unified data type to describe the data, business object to encapsulate the logic, and UI pattern to encapsulate the UI, with this, you can use a simple design tool to quickly describe data, assemble business logic, and establish the UI, this makes the so-called "Mode-driven" development model a reality. The development here is not the development of simple applications, but the development of business processes. This design tool is visual composure.

 

First, we will introduce several concepts:

Service:

A service is a service concept in SOA. It provides a business function of an enterprise.

There are three services in ESA:

Core Service: provides direct access to business objects, such as retrieve, access, action...

Compound service: composed of calls for multiple core services.

Enterprise Service: it is also a compound service, but it is a direct service that forms the business process. It provides key business functions of the enterprise.

 

Business Object:

Bo can be seen as the implementation of the service. The definition of the service has nothing to do with its implementation. SAP mainly uses Bo in the ESA to implement the service function.

Bo is structured. Each Bo is connected by association, but there is only one root node.

A Bo can have multiple service interfaces. A service interface consists of multiple operations.

Bo defines a set of attribute and operation. Each Bo is implemented by a business object provider class, which implements a set of generic interfaces.

The attirbute type of Bo must be global data types (gdt)

 

Global Data Type

To unify the definition of the service interface, you must unify the data type.

 

Business Process:

 

 

LDU (logical Deployment Unit)

A ldu is composed of a set of semantic-related componenet. To make it simple to activate/deactive a service function. s

 

Process agent:

Provides message-based LDU communication.

 

Yesesa implementation:

ESI (Enterprise Service Infrastructure) provides a uniform web service-based service definition for the implementation of ESA. Make Development of "mode-driven" possible. This design starts with the requirement and defines the service and service-driven implementation.

Shows the development mode of ESA:

ESI consists of three parts:

ESD: Enterprise Service designtime: Provides ESI design-time support. There are three projects:

ESR (Enterprise Service repository), including es object, modelling, and ESR framework

Es Java tools, including repository browser, service and consumer definition editor, service configuration and consumer configuration Editor, proxy generation.

Es ABAP tools: Includes repository browser, service and consumer definition editor, proxy generation

ESF: enterprise service framework, which provides the running Implementation of ESI. (It should be called Enterprise Server engine)

ESF runtime architecture,

ESP: Enterprise Service Protocol: defines all ESI protocols