WSO2 ESB Components

This chapter provides the detailed information about the ESB components. Following components are available:

• Template - Using templates is an ideal way to improve reusability and readability of ESB configurations/XMLs. Users can utilize predefined templates that reflect commonly used EIP patterns for rapid development of ESB message/mediation flows.

• Task - This component allows you to run a piece of code triggered by a timer. WSO2 ESB is already bundled with a task, which can be used to inject a message to ESB given by the configuration at a scheduled interval (5000 ms). A user can also write his own task, for example, you can create a task which will read a text file at a specified location and place orders for stocks that are given in the text file.

• Message Processor - This component can be used to implement different messaging and integration patterns along with message stores. Message processors will consume the messages in message stores and do the processing of them. For example, think of a scenario where we have a back end service that can only accept messages at a given rate and incoming traffic to ESB will have different message rates. To serve that traffic utilizing the backend services, we can have a message store that temporary store the traffic and a message processor that will consume that messages and send to the back end service at a given rate.

• Message Stores - A Message store serves as a storage for ESB messages. For example, in a scenario where we have a back end service that can only accept messages at a given rate and incoming traffic to ESB will have different message rates. To serve that traffic utilizing the back end services, there should be a temporary storage for messages. Message Stores can be used as this temporary storage.

• Endpoint - It is external destination for an outgoing message through WSO2 ESB. An <endpoint> element defines an endpoint in the configuration.

• Carbon Application (cApp) - cApp is a collection of artifacts, which can be deployed on a Carbon instance to easily port a Web services based solution from one environment to another.

• Topic - The user can view all the topics available in the server in a tree view with the help of the "Topic Browser" feature. The user can also perform all the operations with regarding a topic via this view.

• Mediation Library - This component provides a mechanism to group Templates and automatically expose them as a self-contained set of function modules.