In the two-phase commit protocol, suppose a cohort crashes in each of the following situations. Explain what should it do when it recovers

(a) It crashed before it sends it vote message

(b) It crashed after it had voted while it was in its uncertain period.

(a) It crashed before it sends it vote message
Solution:
Abort. It knows the coordinator could not have committed the transaction, since it has
not voted.
(b) It crashed after it had voted while it was in its uncertain period.
Solution;
Ask the coordinator was happened, whether the transaction was committed or aborted.