Web services transactions: past, present and future

The concept of atomic transactions has played a cornerstone role in creating today's enterprise application environments by providing guaranteed consistent outcomes in complex multi-party business operations. While numerous multi-party business applications involve various patterns based on atomic transactions, it was not until recently the term "business transactions" accumulated any concrete meaning. Rapid developments in the Internet infrastructure and protocols has yielded a new type of application interoperation that makes concepts which could only previously be considered in an abstract form an implementation reality. The effects of such changes have been felt most strongly in business environments, fueling the mindset for a transition from traditional atomic transactions to extended transaction models better suited for Internet interoperation. The first real attempt at this was the OASIS Business Transaction Protocol in 2001; this was then followed by the Web Services Transactions specification from IBM, Microsoft and BEA in August 2002, and more recently by the Web Services Transaction Management specification from Sun, Oracle and others in August 2003. Although these specifications have some obvious commonality in their approaches, there are significant differences. Unfortunately for developers, the release of three competing specifications has effectively frozen the market. Why are these different specifications required? Have application requirements changed so much over the past two years? Are more specifications going to arise? In this paper we'll try to address some of these questions and give an indication of where we think things will go in the future.