Monday 23 May 2011

Cloud storage



Cloud Storage service

Introduction:

Enterprises nowadays are looking for reducing the costs of using the Information Technology (IT) infrastructure and accelerating the data transfer (Nicolae,2010). Storage infrastructure is the most expense IT's infrastructure. Trends show that the expenditures of the enterprises on the storage infrastructure can be 30%of the capital expenditures. This growth of the expenditure is as a result of the increased demand of data in the organizations (Wu, et. al 2010).  As the size of the storage servers spaces increase, other requires will increase such as: power electronics, servers cooling, ongoing servers' administration, maintenance, etc.
To address the above issues, there is an emerging technology called Cloud Storage service. The term cloud computing was introduced in 2007. It promises to provide comprehensive management and massive storage capacity (Yuan 2010). Cloud storage enables new application types through  SOA, Web services APIs and unified service interface via virtualization over a network at low cost, and can provide anytime and anywhere access, massive data storing, sharing and collaboration via a single namespace, and policy management of storage, etc. The cloud storage services are not only focusing on the large enterprises, but also for the end users (Ge, et.al 2010). 
With the increased use of the web 2.0 technology, many web sites offer high range of data services such as sharing data, video streaming, data backup and downloads. These services are increasingly demanded from the entire globe’s enterprises. When these cloud services are provided in lower cost, high reliability, data security, high performance and professional operators, this can lead to the satisfactory of the service requester (clients) which increases the adoption of the cloud service.   

Benefits of using cloud storage:

Many cloud services have been delivered based on storage infrastructures, like Google Docs , GMail,  Dropbox, Mozy, and Jungle Disk .These services are designed for specific applications which present transparent and friendly cloud access interface for endusers. Without these cloud services, it is impossible to utilize the cloud resource for end users (Xu,et .al 2010).
The below table compares some cloud computing services based on the most leading vendors:
Table 1cloud services comparison source (Buyya, Yeo & Venugopal 2008)

The adoption of providing such service by these companies is based on its benefits. The loosely couple infrastructure characteristic of the cloud storage allows it to response to the business demand regardless of its geographical place.
Cloud storage allows the clients to store and manipulate any type of data on higher-performance, more scalable, more accessible and cheaper storage. Moreover, the clients will not be charged for the management of their data it can free the clients from the costly management overhead that surrounds data storage by serving up file storage in a self-managed, easy-to-access manner. Cloud storage allows clients to store data in XML files, text files, or even the large sized data such as videos, pictures, database files, sounds or torrents many other data formats. Any business or organization choosing cloud storage can save physical space for storing data and thus benefit from a cost effective solution. Cloud computing solutions allow for network versatility and flexibility, which in turn means that the client can manage and control the size of their IT infrastructure within minutes and cut costs on a day to day basis.
Cloud storage provides the flexibility to share data infrastructure across intraregional borders which allows clients to access data from around the globe. Moreover, with this kind of online storage it is easy to add storage in real time to accommodate fluctuation demands.

Evaluation of Cloud storage services:

As any kind of service, clients should evaluate the storage. This kind of evaluation will increase the likelihood of getting the best advantages of this service. The evaluation is usually based on some criteria such as, for example:
1.     Performance: before choosing the cloud storage service, it is important to identify the performance requirements for the company. Most of the cloud vendors provide only 2-3Mbps. This speed is usually insufficient for the data production. The performance should be also tested multiple times as the performance can be inconsistent (Zilbershtein&Ganon2009).
2.     Ease of integration: the accessibility of the data storage is crucial factor in cloud storage. The integration some time becomes difficult. Thus, it is important to ensure that the vendors offer any standards-based integration software that allows access via CIFS, NFS, FTP or HTTP.  
3.     Flexibility: the flexibility of the cloud storage to respond on demand is important. Cloud storage products should provide elasticity, with capacity that grows as client's business requires, and scales back as soon as this excess capacity is no longer needed.
4.     Usage-based billing:  paying only what client uses can increase the adoption of the cloud storage service. “Hidden” fees to watch out for include: connect fees, account maintenance charges, and “puts” and “gets” charges. Cloud platforms should offer simple and predictable monthly bills (Pathan, Broberg & Buyya).

Issues related to the cloud storage:

In spite of the benefits of cloud storage, it has some issue concerned with it.
-      privacy issue: science the cloud service allows the clients to move their owned documents to be managed by third party, the privacy issue is becoming very concerned. If the data is stored in plain text, the user will be able to access this data which reveals the privacy of the data. So, a strong data encryption is needed (Hong-xia, L, Jia-zhu,  D& Chao, J 2010).
-      Self-adaptive storage resource management: the monitored data needs to enable optimized, dynamic control, for large scale data transfer on dedicated circuits, data transfer scheduling, distributed data scheduling, automatic management and performance prediction of remote storage services (Kant 2009).
-      Client monitoring and security: client monitoring needs be ensured the data is being respected by the service provider. In the security aspect, service provider must be aware of the access rights of the different kinds of users in the client side. Further, monitoring is important to detect the malicious access and prevent them by some mechanisms such as (blacking list users and banning access in defined period of time) (Antoniu 2010).



References list



 Buyya, R., C. S. Yeo, et al. 2009, ‘Cloud computing and emerging IT platforms: Vision, hype, and reality for delivering computing as the 5th utility’,Future Generation Computer SystemsVol.25, No.6, pp599-616.

Ganon, Z. &Zilbershtein, I. E. 2009,‘Cloud-based Performance Testing of Network Management Systems’, Computer Aided Modeling and Design of Communication Links and Networks, 2009, CAMAD '09. IEEE 14th International Workshop

Kant, K. 2009, ‘Data center evolution: A tutorial on state of the art, issues, and challenges’Computer Networks, Vol.53, No17, pp 2939-2965.

Liu Hong-xia; Dai Jia-zhu; Jiang Chao, ‘Research on privacy preserving keyword search in cloud storage’, Computer Science and Information Technology (ICCSIT), 2010 3rd IEEE International Conference on , vol.3, no., pp.444-446, 9-11 July 2010
Nicolae, B 2010, ‘High Throughput Data-Compression for CloudStorage’, Proceedings of the 3rd International Conference on Data Management in Grid andP2P Systems 6265 (2010) 1-12

Pathan, M, Broberg, J, et al 2009,Maximizing utility for content delivery clouds, Web Information Systems Engineering - WISE 2009. G. Vossen, D. Long and J. Yu, Springer Berlin / Heidelberg. 5802: 13-28.
           
Wu, J,  Zhang, J, Lin, Z &, Ju, J  2010 ‘Recent Advances in Cloud Storage’, Proceedings of the Third International Symposium on Computer Science and Computational Technology, China, 14-15,August 2010, pp. 151-154

Xu, P, Zheng, W, Wu, Y,Huang, X&XuC 2010,’Enabling Cloud Storage to Support Traditional Applications’, The Fifth Annual ChinaGrid Conference, 2010,Beijing, China,