Distributed Large Data-Object Environments: End-to-End Performance Analysis of High Speed Distributed Storage Systems in Wide Area ATM Networks

We have developed and deployed a Distributed-Parallel Storage System (DPSS) in several high speed ATM WAN testbeds to support several different types of data-intensive appli- cations. Architecturally the DPSS is a network striped disk array, but is fairly unique in that its implementation allows applications complete freedom to determine optimal data layout, replication and/or coding redundancy strategy, security policy, and dynamic recon- figuration. In conjunction with the DPSS, we have developed a "top-to-bottom, end-to-end" perfor- mance monitoring and analysis methodology that has allowed us to characterize all aspects of the DPSS operating in high speed WAN environments. In particular, we have run a variety of performance monitoring experiments involving the DPSS in the MAGIC testbed, which is a large-scale, high-speed, ATM network and we describe our experience using the monitoring methodology to identify and correcting problems that limit the per- formance of high speed distributed applications.