WebSphere Enterprise Service Bus

An Enterprise Service Bus (ESB) is a flexible connectivity infrastructure for integrating applications and services. An ESB can power your Services Oriented Architecture (SOA) by reducing the number, size, and complexity of interfaces between those applications and services.

An ESB performs the following:

• Routing messages between services

• Converting transport protocols between requester and service

• Transforming message formats between requester and service

• Handling business events from disparate sources

An ESB should allow your organization to focus on your core business needs rather that the IT Infrastructure required connecting the programs together. An ESB should allow you to add new services, or make changes to existing services, with little or no impact to the use of existing services.

IBM offers three ESB products: IBM WebSphere ESB, IBM WebSphere Message Broker, IBM WebSphere DataPower Integration Appliance XI50. Selecting an ESB to power your SOA depends upon your requirements. WebSphere ESB is a platform-based ESB and optimized with WebSphere Application server for an integrated SOA platform. WebSphere Message Broker is a platform-independent based ESB and is built for universal connectivity and transformation in heterogeneous IT environments. WebSphere DataPower Integration Appliance XI50 is an appliance-based ESB and is built for simplified deployment and hardened security. Customers face a wide range of ESB requirements from the simple to the complex.

When to Use WebSphere ESB?

• You use WebSphere Application Server and/or your team has skills with WAS Administration and Java coding

• You are now or planning on developing business process using WebSphere Process Server (WebSphere ESB and WPS have common tooling, programming model, and runtime)

• You are integrating with ISV business applications hosted on WAS or 3rd party solutions which extend and support WAS

• You are focused on standards based interactions using XML, SOAP, and WS

• You want to mediate between Web services and existing systems using JMS and WebSphere JCA Adapters

• Reliability and extensive transactional support are key requirements

• You want to minimize your server investment by co-hosting WebSphere services and ESB in one application server

When to Use WebSphere Message Broker?

• You are currently using WebSphere Message Broker but not as an ESB


• You have extensive heterogeneous infrastructures, including both standard and non-standards-based applications, protocols, and data formats
  
  - You have extensive MQ skills and infrastructure
  
  - You are using Industry formats such as SWIFT, EDI, HL7


• You are implementing a wide range of messaging and integration patterns
  
  - Complex event processing, message splitting and aggregation


• You need extensive pre-built mediation support


• You have very complex transformation needs


• Reliability and extensive transactional support are key requirements


• To achieve very high-performance with horizontal and vertical scaling

When To Use WebSphere DataPower?

• Ease of use is a pre-dominant consideration
  
  - Simple experience of drop-in installation and admin-based configuration with no or minimal development required


• You are transforming between XML-and-XML or XML-and-any other format


• Your interaction patterns are relatively simple


• Your mediation requirements are met by the existing DP mediations and minimal extensibility is needed


• You are using XML-based or WS-Security extensively


• You require use of advanced Web services standards


• You need to minimize message latency when adding an ESB layer


• You are doing extensive XML processing combined with high performance requirements


• Your ESB must be in production very quickly

Within a federated ESB model, one may choose a particular ESB based upon their specific requirements. Customers can make WebSphere ESB and Message Broker work together via MQ Link, JMS, and Web services (SOAP over HTTP protocols or JMS over either WebSphere MQ or JMS). WebSphere Message Broker and WebSphere DataPower now have a single tool and security policy description for optimal security requirements. With a simple click with WebSphere Message Broker, DataPower will perform WS-Security processing. Applications and message flows will remain unchanged.

Larger, heterogeneous enterprises often appear as a federation of somewhat autonomous domains based on lines of business, functional or governance areas. In such environments, some services may be shared or reused only within a single domain, while others may be shared or reused throughout the enterprise. In these situations, we recommend some form of ESB federation that matches the needs of the domain federation. ESB federation allows different ESB products to be used in different domains, allowing an optimal match between domain requirements and product capabilities. The roadmap and reference architecture should provide guidelines and even options for product selection for any given domain to ensure enterprise-wide optimization. We further recommend use of a federated service registry and repository to assist enterprise-wide management and governance of reusable services across the enterprise.

WebSphere Message Broker includes the WebSphere Message Broker toolkit which is based on the Rational Software Development Platform which itself is built on Eclipse. The toolkit runs on either Windows or Linux on Intel, and enables the customer to configure the system, develop the message flows and manage deployed environments. The toolkit also provides visibility of adapters (remote or local) in a Broker message flow.

WebSphere Integration Developer, or WID, is the tool for use with both WebSphere ESB and WebSphere Process Server. WID is designed to be an easy-to-use tool, targeted at the Integration Developer. WID is built on the Rational Software Development Platform which itself is built on Eclipse. WID does not require the user to be a Java developer in order to build and deploy mediations; however it is can be integrated with Rational Application Developer (RAD) for those customers who wish to write their own Java code.

WebSphere Message Broker and WebSphere MQ address different business needs. WebSphere MQ provides secure and reliable connectivity between application and systems, supported on more than 80 platform configurations. This provides the ability to move data unchanged between virtually all business environments likely to be deployed in a business infrastructure. WebSphere Message Broker is used as a transport for moving data between applications, but it is capable of performing additional tasks through understanding of data formats, allowing it to provide intelligent routing and transformation of XML data formats. Businesses will still see a need for WebSphere MQ to connect up the multiple different environments that make up the typical IT infrastructure deployed around an enterprise, but are likely to see a need for an ESB to add value in environments where it can act on the structured data being exchanged between standards-based applications.

Because WebSphere ESB is built on WebSphere Application Server, through their WebSphere ESB license; customers are able to utilize WebSphere Application Server function. In addition, WebSphere ESB also includes additional functions not supplied with WebSphere Application Server. WebSphere ESB is likely to appeal to many WebSphere Application Server customers who are looking to integrate applications running in their enterprise, who do not want to implement the integration required to link the applications by coding bespoke application logic, either within the application programs themselves or by coding additional adapter logic. WebSphere ESB will allow the integration of applications with minimal programming, with the integration logic being performed on the data 'in-flight' between applications.

WebSphere Process Server is powered by the same technology available with WebSphere ESB. This capability is part of the underlying functionality of WebSphere Process Server and no additional license for WebSphere ESB is required for WebSphere Process Server to take advantage of these capabilities. However customers may choose to deploy additional standalone licenses of WebSphere ESB around their enterprise to extend the connectivity reach of the process integration solutions powered by WebSphere Process Server. For example, WebSphere ESB could be installed closer to an SAP application to host a WebSphere Adapter for SAP and to transform SAP messages before sending that information across the network to a business process choreographed by WebSphere Process Server.

WebSphere ESB solves a different aspect of integration than WebSphere BI Server Express or WebSphere BI Server Express Plus. WebSphere ESB provides integration focused on standards based applications and services. WebSphere BI Server Express is designed for integrating inefficient stand-alone manual processes that might involve business processes which span multiple applications and systems, including packaged applications. As part of the product license, some adapters are included with WebSphere BI Server Express to facilitate the connection and integration of key packaged applications. Therefore the scope and capabilities of the expected use of WebSphere BI Server Express is different to the capability set for WebSphere ESB, which is more directly focused on the rapid integration of applications and services built to comply with web services standards requiring minimal integration programming. However WebSphere ESB can also make use of WebSphere adapters to integrate with external applications, but these must be purchased at additional cost.