Spring 2008 CIS 455 555 Internet and Web Systems Final Examination 120 minutes 8 questions 120 pts Try to allocate no more than 1 minute per point and be concise with your answers Your name 1 For the PageRank algorithm improved version a explain its intuition in terms of the authoritativeness b explain it with respect to the random surfer model c specify how it is computed in matrix form including how the matrices are created 20pts 2 a BRIEFLY explain what strictness means and its importance in isolation 5pts b Provide an example in which locks are used but not acquired and released according to the two phase convention which results in a lack of isolation 5pts 3 Explain how a master coordinator node in two phase commit goes through the recovery process consulting its logs if it crashes in the middle of a vote 10pts 4 Outline the steps for taking a keyword query of the form k1 k2 and returning answers in the document vector model based on TF IDF 20pts 5 Write the map and reduce functions that given a distributed list of documents count all documents with names starting with c which include at least ten keywords starting with k 10pts 6 Explain the roles of the principals nodes and the authentication steps in the Kerberos protocol 20pts 7 Provide pseudocode showing how one would use Pastry to GET a value by key Describe the failure cases and how Pastry handles them if at all 10pts 8 Given an XML version of an inverted index over English documents inverted xml of the form index entry word word foundIn foundIn entry index where s mean 0 or more elements and a table of French word translations french xml of the form english french word english english french french word english french Write an XQuery that takes the word universit and returns the set of corresponding entries 20pts