Some functions modify a large amount of data taking a long time to complete the operations. For example, deleting products, importing users and discount coupons, removing temporary images, and so on.
in these cases the procedures are broken up into several stages using ajax. At the end of each phase, the user log is updated, visible right next to the relative button, and a special button is made available to interrupt the entire operation.
At the end of the operations the user log will be useful to have a report of what has been done.