Abstract
Many modern applications, from Grid computing to RSS handling, need to support data processing in a distributed environment. Currently, most such applications are implemented using a general purpose programming language, which can be expensive to maintain, hard to configure and modify, and require hand optimization of the distributed data processing operations. We present Distributed XQuery (DXQ), a simple, yet powerful, extension of XQuery to support distributed applications. This extension includes the ability to deploy networks of XQuery servers, to remotely invoke XQuery programs on those servers, and to ship code between servers. Our demonstration presents two applications implemented in DXQ: the resolution algorithm of DNS, the Domain Name System, and the Narada overlay-network protocol. We show that our system can flexibly accommodate different patterns of distributed computation and present some simple but essential distributed optimizations.