James R. H. Challenger

Efficiently serving dynamic data at highly accessed web sites

We present architectures and algorithms for efficiently serving dynamic data at highly accessed Web sites together with the results of an analysis motivating our design and quantifying its performance benefits. This includes algorithms for keeping cached data consistent so that dynamic pages can be cached at the Web server and dynamic content can be served at the performance level of static content. We show that our system design is able to achieve cache hit ratios close to 100% for cached data which is almost never obsolete by more than a few seconds, if at all. Our architectures and algorithms provide more than an order of magnitude improvement in performance using an order of magnitude fewer servers over that obtained under conventional methods.

Improving the accessibility of aurally rendered HTML tables

Current techniques employed to aurally render HTML tables often result in output that is very difficult for sight-impaired users to understand. This paper proposes TTPML, an XML-compliant markup language, which facilitates the generation of prose descriptions of tabular information. The markup language enables content creators to specify contextual reinforcement of, and linear navigation through, tabular information. The markup language may be applied to pre-existing Web content and is reusable across multiple tables. TTPML may be interpreted by origin servers, proxy servers, or browsers. We believe that our approach benefits sight-impaired users by improving accessibility to tabular information.

Monitoring distributed systems: a publish/subscribe methodology and architecture

To support complex, rapidly changing, high-volume Web sites many components contribute to keeping the content current. Monitoring the workflow through all these components is a challenging task. This paper describes a system in which monitoring objects created by the various heterogeneous, distributed components are distributed to any application choosing to present monitoring information.

Monitoring Distributed Systems

To support complex, rapidly changing, high-volume websites many components contribute to keeping the content current. Monitoring the workflow through all these components is a challenging task. This paper describes a system in which monitoring objects created by the various heterogeneous, distributed components are distributed to any application choosing to present monitoring information.