Assume a cohort in the two-phase commit protocol crashes in each of the following situations. When it restarts later, explain what it does and why.
(a) Before receiving the prepare message.
(b) After receiving the prepare message but before it votes
(c) After sending its vote message saying it is ready to commit
(d) After receiving the commit message but before it completes its commit processing
(a) It aborts because the coordinator will abort the entire transaction when it does not receive a reply to its prepare message.
(b) It aborts because the coordinator will abort the entire transaction when it does not receive a reply to its prepare message.
(c) It sends a message to the coordinator asking what the nal status of the transaction was and then acts accordingly
(d) It completes its commit processing.
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Using inheritance allows us to
a. eliminate duplicate code b. make our classes more modular c. use polymorphism d. all of the above e. none of the above
The most realistic type of penetration test is a ____ box test.
A. black B. gray C. red D. white
The components of a class are called the ____ of the class.
A. operators B. friends C. objects D. members
In the constructor for the ArrayBag class shown below, what is the missing code?
def __init__(self, sourceCollection = None):
A. items.add(self) B. self.items = Array(ArrayBag.DEFAULT_CAPACITY) C. self.items = ArrayBag.add(sourceCollection) D. add.items(self, sourceCollection)