Julunga: A New Large-Scale Distributed Read-Write File Storage System for Cloud Computing Environments

Abstract

We present in this paper the design of a large distributed file storage system called Julunga for cloud computing environments. Julunga is designed for federated data center environments where multiple numbers of data centers across the globe interconnect to each other and present a coherent single system view to end-users. In Julunga, the metadata, the namespace and the data blocks of the files are completely distributed with no hard limits on the number of files that can be accommodated in a single directory. Also, there is no physical limit on the size of a file. Julunga supports file of exabytes size with ease along with the number of concurrent users updating, reading and writing to the same file or a directory. The location of the data blocks of a file is determined by using functions, thus expunging the need for file allocation tables. Many new data structures and algorithms were designed earlier where locality and preferences of users are considered to provide optimal storage locations for files and metadata. We elaborate, in this paper, the design of fundamental building blocks of the distributed storage system and compare it with the designs of the earlier file storage systems.