Remote Update Research Articles

WebSYL: An Internet Based Electronic Syllabuses System

The WebSYL system for the Electronic Syllabuses of the Faculty of Engineering, Saitama University is developed. The system contains 460 entries for the lectures of all of the 6 engineering departments. The WebSYL system includes programs to automatically convert the database to hypertext format, programs for automatic generation of syllabuses entries by the instructors, form based and frame based search engines and a bilingual search engine for keyword search. An important feature of this system is the automatic remote update facility for the entries. This is done via using agent technology and developing CGI and plug-in software that take care of the state of the access. In this way instructors can update syllabuses entries from remote clients using ordinary browsers and the state of the edit is preserved in the forms. By automating the update process the problem of manual maintenance of the syllabuses entries is totally removed.

Site Partitioning for Redundant Arrays of Distributed Disks

Redundant arrays of distributed disks (RADD) can be used in a distributed computing system or database system to provide recovery in the presence of disk crashes and temporary and permanent failures of single sites. In this paper, we look at the problem of partitioning the sites of a distributed storage system into redundant arrays in such a way that the communication costs for maintaining the parity information are minimized. We show that the partitioning problem is NP-hard. We then propose and evaluate several heuristic algorithms for finding approximate solutions. Simulation results show that significant reduction in remote parity update costs can be achieved by optimizing the site partitioning scheme.