Reliable Messaging on the Internet
In addition to transactions, SkatesTown's Dean Caroll wants to use other means to reliably transmit messages over the Internet. Unfortunately, despite some ongoing efforts, there is still no broadly accepted standard in reliable messaging. As in security technologies, we can approach this issue at the two levels: messaging and transport.
An example of a messaging-level approach can be found in the ebXML Transport, Routing and Packaging (ebXML TRP) specification. It defines the MessageHeader element, which is present as a child of the SOAP header element; this element can contain a collection of parameters to perform reliable messaging in a transport-agnostic manner. Although this specification is well described, it is unfortunately not broadly accepted at this moment.
JMS, as described in this section, is an approach for reliable messaging. However, it requires transport products other than HTTP, such as IBM MQ Series. Recently, IBM announced HTTPR to provide HTTP with reliability and asynchronicity features. There is some commonality between TRP and HTTPR models; for example, they both assume message handlers are present at the sender and receiver sides. Accordingly, their protocols are similar. The big difference is whether their parameters are defined as a SOAP header entry or HTTP headers. HTTPR is IBM-proprietary, so whether it will be widely accepted is not certain.