Introduction

The consequence of not thinking about reliable communication or not implementing it in our OSB services can lead to many problems in case of error. It can lead to the loss of your messages, a destination can receive multiple messages and this means that the sending application can't trust the service bus. The application needs to monitor its own requests.

Reliable communication is all about Distributed Transactions—XA, Quality of Service (QoS), and persistence.

XA is a transaction that can be shared across multiple resources such as a JMS queue, coherence, direct binding, JCA binding, or an EJB session bean. Be aware that the HTTP transport does not support XA and can't take part in the so called global transaction. When an OSB transport or a JCA adapter starts a transaction, this transaction will be handled or controlled by the Java Transaction API (JTA) of the WebLogic server. XA will use a two-phase commit so all resources either do a commit or a rollback together.

When a destination...