In the above paper, we have expounded a simple and reliable messaging framework for distributed scientific applications.
The use of SOAP/XML makes it flexible enough to interoperate with messaging systems on different platforms. This also makes it possible to extend its use as a grid Web Service, offering a candidate for a messaging system on the grid. One downside of using XML is that the performance of transmitting a message on the wire degrades compared to a binary protocol. But we do not perceive this to be a bottleneck for application level messaging that is primarily concerned with coordinating and monitoring.
The publisher/subscriber interface allows 'pull' and 'push' retrieval of messages and these alternatives gain significance in a distributed environment having firewalls and NATs. Using the agents as intermediaries for the publisher and listener ensures reliable delivery of messages and allows for recovery from most failure conditions. The message channel supports a mechanism for asynchronous message passing on a many to many basis among publishers and listeners. In addition, it allows for persistent storage of messages and versatile means for querying historical events.
We believe that the XMessages framework provides a feature rich yet light weight messaging system for grid based applications.