http://dev.mysql.com/doc/refman/5.7/en/xa.html warns that "However, for a distributed transaction, you must use the SERIALIZABLE isolation level to achieve ACID properties. It is enough to use REPEATABLE READ for a nondistributed transaction, but not for a distributed transaction.)"
The docs don't make it clear what ACID properties fail to be achieved when using isolation levels of REPEATABLE READ (or below, such as READ COMMITTED).
Does the documentation mean that REPEATABLE READ won't offer REPEATABLE READ semantics in a distributed transaction?
What happens if I use lower isolation levels such as READ COMMITTED? Is the promise of READ COMMITTED going to be violated?