Cloud computing: cost, security, and performance

The cloud computing systems face challenges from various aspects, including deployment cost, security, and performance. This project surveys these challenges and the approaches to addressing them. Deployment cost is an intense challenge to cloud computing. The high network bandwidth required to support potentially millions of users is a key aspect that leads to the rising costs for cloud service providers. To alleviate the bandwidth consumption, lightweight frameworks such as Angular have been developed to reduce the bandwidth necessary to transmit the required data by allowing clients to optimize and interpret the data rather than sending large files over a network. Video streaming codecs have adapted to keep high quality images, while lowering the amount of bandwidth needed to deliver the high definition video. Security is a critically important aspect of cloud services. User's data is at risk of being intercepted when it is transmitted across an unsecured network. Approaches to solving the problem of network security include data encryption and the use of Virtual Private Network (VPNs). Encryption prevents private data from leaking to unwanted users, with the cost of relatively high computational overhead. VPNs allow data to be delivered securely between authenticated end-points via a sub-network defined over a public underlying network. In addition to the networks, cloud servers themselves may be vulnerable to security attacks, both internally and externally. Internal attacks can be rogue administrators, exploiting cloud vulnerabilities, and using the cloud to conduct "nefarious activity". The damages range from stealing unprotected files to using the servers as tools to attack other organizations or users. External attacks include cross site scripting, information leakage and improper handling, broken authentication and session management, failure to restrict Web access, improper data validation, insecure communications, and malicious file execution. To resolve the security concerns on the cloud servers, various technologies have been developed, including storage with encryption, firewalls, packet filters, as well as virtual local area networks. Performance is another very important issue in cloud computing. Poor performance can be caused by various factors, including improper use of hardware resources on either end of the connection, and the network latency. From the hardware aspect, an effort to improve performance has been the move towards flash-based storage in order to increase read/write speeds and therefore decrease access times. In addition, parallel computing allows more work to be done in the same amount of time and significantly benefits large cloud server systems that run thousands of systems in parallel. Deploying small data centers closer to the end-users can help significantly reduce the latency perceived by users as well as the workload on the main datacenters, at the cost of increased deployment expense for cloud service providers and content distribution networks.