This paper presents, in the form of a case study, the design, implementation and performance evaluation of Phoenix: a prototype of a fault-tolerant distributed storage web service based on URLs. Our system supports a set of redundancy strategies including simple file-replication, error-coding techniques and a hybrid adaptive technique. The web storage middleware (WSM), which is at the core of the prototype, reuses the URLs of the files to dynamically accommodate data and redundancy load. Experimental assessments show that distributing the users to several web servers compensates for the overhead produced both by generating and distributing data redundancy. We also found that during a non-critical number of web server failures, users do not perceive but a lengthening on the system response times. As expected, peak user requests and network congestion are the most important factors affecting the storage system’s performance.
목차
Abstract I. INTRODUCTION II. RELATED WORK III. PHOENIX DESIGN PRINCIPLES A. WSM: A Web Storage Middleware B. Redundancy Strategies C. Redundancy based on Simple Replicas D. Redundancy based on IDA IV. DESIGN OF EXPERIMENTS A. Studied Configurations B. Studied Measurements V. RESULTS A. Upload Operations B. Download Operations C. Degraded Mode and Redundancy Costs VI. CONCLUSIONS VII. FUTURE WORK ACKNOWLEDGMENT REFERENCES