Commits the current transaction.
The transaction's log is reset if the commit was successful, otherwise it still retains in the transaction which must be successfully committed, aborted or reset in order to be (re-)used for another request.
@throws ConnectionException if the connection is not active or a communication error occurs or an exit signal was received or the remote node sends a message containing an invalid cookie
@throws TimeoutException if a timeout occurred while trying to commit the transaction
@throws AbortException if the commit failed
@throws UnknownException If the commit fails or the returned value from erlang is of an unknown type/structure, this exception is thrown. Neither the transaction log nor the local operations buffer is emptied, so that the commit can be tried again.
@see #abort()