O.k., it's pet peeve time. Otherwise intelligent people seem to get really confused whenever they hear "two phase commit". They immediately assume that if one is using two phase commits then one must be implementing an ACID or at least Atomic transaction. Nonsense! A two phase commit is nothing more than a coordination mechanism. It allows one to guarantee that a group of independent systems will either all perform or all not perform a particular action. Historically the 'action' was usually some kind of ACID or at least Atomic transaction. But there is nothing in two phase commits that requires or even implies any particular action, atomic, ACID or otherwise.

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