One of the most widely used services in many distributed systems is Essay

One of the most widely used services in many distributed systems is the File Service. Investigate the issue of distributed file systems - Essay Example These challenges will be discussed in this section and also there will be a description of the main architectural features of the Network File System version 4 in relation to its previous versions. Adrian, Teodora and Naiana (2011, p. 801) say that in distributed file systems, caching is an approach that is used to reduce the traffic within the network. Moreover, Tanenbaum and Van Steen (2007, p. 276) emphasize that through catching the reliability and speed of access of data from the server is significantly increased. This means that the users of the system are able to access data with a guarantee of no delays in retrieval. Additionally, caching is aimed at preventing repeated access same data or information. It is through catching that access to data within a system is attained by one user without the redundancy which often results from many users requiring to access, retrieve or modify the same data at the same time. Tanenbaum and Van Steen (2007, p. 277) illustrate that unlike server access, which costs thousands of instructions, cache access is faster as it only costs the client terminal hundreds of instructions. Ainsworth (2009, p. 22) argues that the problem of consiste ncy can be overcome by implementing a write-through technique within the cache policy. The reliability of a write-through cache is relatively high. A delayed write approach may also be used because it saves remote writes, but has relatively poor reliability, especially in situations of a system crash. Caching techniques are designed so that the cached copies of files are presented to the user from the server in an effective manner. Therefore, users have access to the cached copy of files instead of contacting the server directly which mightlead to an overload of the network. According to Dolev and Kat (2005, p. 135), caching presents a challenge of consistency within the processes of file sharing and transfer within a distributed file system. This problem results from the difficulties