Message processor (New in version 4.0) 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 Processor Configuration
<messageProcessor name="string" messageStore="classname" >
<parameter name="string" > "string" </parameter>*
</messageProcessor>
Message processor is a top level ESB configuration element where it should have a unique name. Class attribute value is the fully qualified class name of the underlying message processor implementation.
There can be many message processor implementations.Users can write their own message processor implementation and use it. Parameters section is used to configure the parameters that is needed by underlying message processor implementation.
Users can write there own message processor implementation and plug them using the configuration. WSO2 ESB ships two message store implementations:
WSO2 ESB allows add, edit, delete, activate/deactivate message processors and perform scheduled message processor operations.