Does Message Sampling Processor in WSO2 ESB support reliable messaging

Question

In WSO2ESB the message sampling processor de-queues the messages from the queue and forward it to a sequence where we can do transformation to the request and send to the back - end. And The main purpose of using MSMP is for archiving guaranteed delivery, or in other words, to archive reliable messaging. [Source]

But when we use Message Sampling Processor it just forward the message to sequence and the processor doesn't know whether the message successfully delivered to the back end (using send | call mediator) or the processor knows this and restore the message in the queue? I tried this scenario using JMS-Message Store ( WSO2MB ) and what I found is, message get lost when the back end service is down.

Answer 1

Message Sampling processor does not support reliable messaging[1]. For reliable messaging you will have to use Message Forwarding processor[2]

[1] - https://docs.wso2.com/display/ESB481/Message+Sampling+Processor

[2] - https://docs.wso2.com/display/ESB481/Message+Forwarding+Processor