ARCO: A Long-term Digital Library Storage System Based on Grid Computational Infrastructure

Over the past several years the large scale digital library service has undergone enormous popularity. Arco project is a digital library storage project in Portuguese National library. To a digital library storage system like ARCO system, there are several challenges, such as the availability of peta-scale storage, seamless spanning of storage cluster, administration and utilization of distributed storage and computing resources, safety and stability of data transfer, scalability of the whole system, automatic discovery and monitoring of metadata, etc. Grid computing appears as an effective technology coupling geographically distributed resources for solving large scale problems in the wide area or local area network. The ARCO system has been developed on the Grid computational infrastructure, and on the basis of various other toolkits, such as PostgreSQL, LDAP, and the Apache HTTP server. Main developing languages are C, PHP, and Perl. In this paper, we discuss the logical structure sketch of the digital library ARCO system, resources organization, metadata discovering and usage, the system's operation details and some operations examples, as also the solution of large file transfer problem in Globus grid toolkit