Content Delivery Policies in Replicated Web Services: Client-Side vs. Server-Side

Replication of Web Services has an important role among techniques that have been developed in order to meet the demand for faster and more efficient access to the Internet. Replication can be addressed both by a cluster of servers, and by servers geographically distributed in the Internet. In this paper, we focus on geographical replication. Two approaches are commonly used for geographical replication: server-side and client-side. In the client-side approach, the client has a significant role in the policy used to exploit Web Service Replication. In the server-side approach, the client transparently exploits a Replicated Web Service. Both server-side and client-side approaches provide various strategies that can be adopted. An analysis of these strategies, and an overall classification, is presented here. Finally, client-side and server-side approaches are compared, identifying their pros and cons in order to propose the features of an eventual complete approach.     

Sharing digital micrographs and other data files between computers

It ought to be easy to exchange digital micrographs and other computer data files with a colleague even on another continent. In practice, this often is not the case. The advantages and disadvantages of various methods that are available for exchanging data files between computers are discussed. When possible, data should be transferred through computer networking. When data are to be exchanged locally between computers with similar operating systems, the use of a local area network is recommended. For computers in commercial or academic environments that have dissimilar operating systems or are more widely spaced, the use of FTPs is recommended. Failing this, posting the data on a website and transferring by hypertext transfer protocol is suggested. If peer to peer exchange between computers in domestic environments is needed, the use of Messenger services such as Microsoft Messenger or Yahoo Messenger is the method of choice. When it is not possible to transfer the data files over the internet, single use, writable CD ROMs are the best media for transferring data. If for some reason this is not possible, DVD-R/RW, DVD+R/RW, 100 MB ZIP disks and USB flash media are potentially useful media for exchanging data files.     

Sharing digital micrographs and other data files between computers

It ought to be easy to exchange digital micrographs and other computer data files with a colleague even on another continent. In practice, this often is not the case. The advantages and disadvantages of various methods that are available for exchanging data files between computers are discussed. When possible, data should be transferred through computer networking. When data are to be exchanged locally between computers with similar operating systems, the use of a local area network is recommended. For computers in commercial or academic environments that have dissimilar operating systems or are more widely spaced, the use of FTPs is recommended. Failing this, posting the data on a website and transferring by hypertext transfer protocol is suggested. If peer to peer exchange between computers in domestic environments is needed, the use of Messenger services such as Microsoft Messenger or Yahoo Messenger is the method of choice. When it is not possible to transfer the data files over the internet, single use, writable CD ROMs are the best media for transferring data. If for some reason this is not possible, DVD-R/RW, DVD+R/RW, 100 MB ZIP disks and USB flash media are potentially useful media for exchanging data files.