for recent unpublished
papers on Source Selection for WAA.
Recent advances in technology has enabled wide area application (WAA) processing. This has caused a paradigm shift that has had a significant impact on the techniques used to select and locate information sources. In order to be scalable and flexible, WAA processing must be responsive to client specification of Quality of Access and Content (QoAC) requirements corresponding to the contents and capabilities of sources.
We consider a number of parameters of Quality of Access and Content (QoAC) metadata, to describe the contents and query processing capabilities of sources. Query processing at the client can be characterized by the latency (delay) to access the source, and other access costs associated with a source. Typical parameters for Quality of Access may include: TimeToFirst tuple; TimeToLast tuple; TimeToTopN tuple; $$ Access Cost; etc. Quality of Content metadata describe the source contents. They include the following: Domain information; Recency of Last Update and Frequency of Update; etc.
A characteristic of the wide area environment that poses a significant
challenge to WAA processing is the wide variability in the
availability of metadata.
Sources are autonomous, and may not participate
in a federation to provide such metadata.
The dynamic WAN environment is typically characterized by wide
variability of latency (delays) that depend on server and network
workloads.
Finally, rather than replica servers with
identical contents, mirrors, portals and client caches
differ considerably in their Quality of Content metadata.
for recent unpublished
papers on Source Selection for WAA.