Client/Server Computing:

Q31. With release consistency, the programmer is responsible for inserting explicit code in the program stating when to do the operations, for example, by calling library procedures such as acquire and release or procedures such as enter_critical_region and leave_critical_region. a. true b. false Q32. Weak consistency models have which three of the following properties: (1) Accesses to synchronization variables associated with a data store, are sequentially consistent.(2) No operation on a synchronization variable is allowed to be performed until all previous writes have completed everywhere. (3) Writes from different processes may be seen in a different order by different processes. (4) No read or write operation on data items are allowed to be performed until all previous operations to synchronization variables have been performed. a. 1, 2, and 3 b. 1, 2, and 4 c. 1, 3, and 4 d. 2, 3, and 4 Q33. Using an anti-entropy update model, a server P picks another server Q at random, and subsequently exchanges updates with Q. The approach used is: a. P only pushes its own updates to Q. b. P only pulls new updates from Q. c. P and Q send updates to each other in a push-pull approach. d. Any of these may be used. Q34. Using synchronization variables to partly define consistency leads to what is called weak consistency. a. true b. false Q35. The consistency models in which operations are globally serialized are the most important and widely applied models. a. true b. false