International Journal of Computer Applications (0975 – 8887) Volume 163 – No 5, April 2017 6 A Performance Evaluation of Dropbox in the light of Personal Cloud Storage Systems Abdullah Talha Kabakus Abant Izzet Baysal University IT Center Resul Kara Duzce University Faculty of Engineering Department of Computer Engineering ABSTRACT Personal cloud storage services have attracted the attention of users thanks to this great accessibility. Personal cloud storage services allow users to synchronize their local files with the servers in the cloud in order to make them accessible from anywhere, on any device, and at any time thanks to the client applications provided by the vendors. Various experiments are evaluated on Dropbox, one of the most popular personal cloud storage services, in order to reveal how they affect the performances of file operations such as downloading files from the cloud storage, uploading files to the cloud storage, and deleting files from the cloud storage. The experimental results are discussed with revealing the insights about how the file operations are performed on Dropbox. Also, we discuss the several techniques and architectural design principles provided by Dropbox in order to improve the file synchronization performance in terms of required time and stability. Even though we focus on Dropbox, the proposed study gives an idea about the architecture of personal cloud storage services in general and how can they be improved in terms of performance, security, and usability. We conclude the paper with discussing the features to evaluate personal cloud storage services. General Terms Data Management, Cloud Storage, Cloud Systems Keywords cloud storage, personal service, performance, Dropbox, evaluation 1. INTRODUCTION Personal cloud storage services allow users to synchronize their local files with the servers in the cloud in order to make them accessible from anywhere, on any device, and at any time thanks to the clients provided by the personal cloud storage service vendors. Cloud storage services have gained more popularity day by day since (1) they backup users local files in the cloud, (2) they allow sharing the local files of users between their other devices thanks to the provided client applications developed for the various operating systems, (3) they allow distributed and collaborative work since the files in the cloud are being automatically synchronized with the shared users, and (4) most of these services provide their services for free or reduced prices with respect to current storage services. Comparisons of the available cloud storage services tend to be based on (1) ease of use, (2) stability, (3) security, (4) performance, (5) quality of experience (QoE), and (6) price [1,2]. The competition between the available cloud storage services causes decreasing the cost per GB [3]. According to a recent report by CIO 1 , the global public cloud market will top $146 billion in 2017, up from just $87 billion 1 http://www.cio.com in 2015 and is growing at a 22 percent compound annual growth rate [4]. A comparison of the most well-known personal cloud storage services is listed in Table 1. Table 1. A comparison of the most well-known personal cloud storage services Criteria Dropbox 2 MEGA 3 Google Drive 4 OneDrive 5 File size limit 10GB; Unlimite d With Desktop Client Unlimite d 5 TB 10 GB Size of provided free storage 2 GB 50 GB 15 GB 5 GB Online editing No No Yes Yes File versioning Yes Yes Yes Yes Selective synchronizatio n Yes Yes Java SDK for standalone applications Yes Partial; based on C++ Deprecated ; uses OAuth 2.0 No Support for Linux Yes Yes No No Support for Windows Yes Yes Yes Yes Support for MacOS X Yes Yes Yes Yes Support for Android Yes Yes Yes Yes Support for iOS Yes Yes Yes Yes According to several reports, Dropbox is currently the most used cloud storage service [5–7] which provides 2 GB cloud storage for free despite that both Google Drive and OneDrive have advantages of proving their personal cloud services embedded into another service accounts which are mail and operating system accounts, respectively. According to the Google Trends 6 , the popularity comparison of three most 2 https://dropbox.com 3 https://mega.nz 4 https://drive.google.com 5 https://onedrive.live.com 6 https://trends.google.com