Different points of method "isReady" in HadoopIndexTask

Current code of method “isReady” in HaddopIndexTask use JodaUtils.umbrellaInterval to produce a wider interval to lock task.

That means if there is a task with interval[“2015-09-10/2015-09-11”,“2015-09-14/2015-09-15”] running, the interval of task lock will be [“2015-09-10/2015-09-15”].

Then, if a new task with interval[“2015-09-12/2015-09-13”] is submitted, it will be in waiting list instead of running directly.

Why not let the new task with interval[“2015-09-12/2015-09-13”] running directly by set the lock interval[“2015-09-10/2015-09-11”,“2015-09-14/2015-09-15”].