ajax cache enable and ajax concurrency!

Today, forget to close ajax cache which leads to duplicate result from cache

as to Jquery, this way, I do not need to create some math random token for browser. Just for a memento.禁止浏览器缓存

$.ajaxSetup({cache:false})

Q: ajax concurrency in jquery ajax, two ajax request almost same time, the previous one is overwritten by the 2nd, i.e. 1st failed

A:  in process