Question: (a) Create an example of incorrect operation, analogous to that of Fig., for the master slave initialization protocol under the assumption that a node, after recovering from a node failure, starts in the up state and initializes by first sending DISC and then INIT. Hint: Use the same structure as Fig.; that is, assume that after each failure, node A receives the messages from H that were generated by H in response to the messages in the earlier period at A.
(b) Now suppose that an arbitrary protocol is being used for initialization. It is known that node A. on recovery from a failure, will send message x. Node B. on recovering from failure and receiving message x, will send message y. and node A, upon receiving y under these circumstances, will be correctly initialized. Construct a sequence of failures and delays such that the protocol fails, assuming only that the nodes operate as above under the above conditions. Hint: Follow the hint in part (a), but also assume a sequence of failures at B, with B receiving responses in one period to messages in the preceding period.
