Building Robust Heterogeneous Asynchronous XML Pipelines

We shall present an interactive demonstration of asynchronous XML pipelines. To begin we shall show linear XQuery pipelines developed with a recursive pull pattern. We shall demonstrate that this pattern can be improved by developing pipelines using a declarative scheduling language (DPML). We shall demonstrate in-pipe exception handling, we shall also show pipeline breakpoints and pipeline debugging. In addition we shall show modular pipeline decomposition and layered pipelines written in both declarative and procedural languages.

We shall demonstrate heterogeneity within pipelines - both in terms of the particular XML technology deployed as a pipeline stage (XQuery, XSLT, Validation ...); but also how each stage's implementation may be developed with a preferred XML object model (DOM, SAX, JDOM ...) and show transparent object model conversion within a pipeline.

Finally we shall demonstrate forking and joining of asynchronous XML pipelines and show how such techniques dramatically enhance pipeline throughput when processing results from high-latency sources.