activiti uses DBIdGenerator default, when the id block used up, it will request for another block from db, and increase its
current id status, but I am wondering when will the operation of writing id back to db be performed,
if in the same transaction with other operation like update history identity_link, history_task_instance, what will occur when exception arisen? the id in DbIdGenerator wont rollback, and the new id wont commit to db, so next time it request for new block will result in using the old ids?
what I am missing?