Phoenix: A Fault-Tolerant Distributed Web Storage Based on URLs

This paper presents, in the form of a case study, the design, implementation and performance evaluation of Phoenix: a prototype of fault-tolerant distributed storage web service, based on URLs. Phoenix includes Web Storage Middleware (WSM) that re-uses the URLs of the files to accommodate data/redundancy load dynamically as well as a set of redundancy strategies. Strategies include simple file-replication, error-coding techniques and a new hybrid adaptive technique. Experimental evidence on performance shows that distributing the users to several web servers compensates the overhead produced both when generating and distributing data redundancy. We also found during web server failures, users do not perceive but a lengthening on the system response times. As it could be expected, peak users requests and network congestion are the most important factors affecting the performance of storage system.