You can get different qualities of service with WS-ReliableMessaging, depending on the level of durability and transaction support provided by the store used to manage the reliable messaging state. These qualities of service range from protecting against loss of messages across a network, through to protecting against server failure.
WebSphere® Application Server provides the following three qualities of service for WS-ReliableMessaging when using a SOAP over HTTP binding. All three qualities of service are supported when applications are deployed to the application server. Thin client and client container applications use the first option only.
When the web service application invokes the web service, the SOAP message is added into the WS-ReliableMessaging store. For the Managed qualities of service, the sending application transaction is used to put the message into the message store. After the transaction commits, the message is eligible for delivery. The other quality of service option is not transactional, so it considers the message eligible for delivery immediately.
The WS-ReliableMessaging protocol is used to reliably deliver the message to the target server where it is stored and acknowledged.
The message is read from the store and dispatched to the receiving application. For the Managed Persistent quality of service, a transaction is used to read the message and then dispatch the application.
For more information about using WS-ReliableMessaging transactions, see Providing transactional recoverable messaging through WS-ReliableMessaging.
The managed qualities of service, managed persistent and managed non-persistent, are supported by the service integration bus. For each attachment between an application and a policy set, you can select the bus and messaging engine to use for the reliable messaging protocol state.