Hi, Sorry. A false alarm. Got mistaken with what IDEA calls "unused" may not really be unused. It is (re)assigned in StageInfo.fromStage for a ShuffleMapStage  and then caught in ExecutorMonitor  (since it's a SparkListener).
 https://github.com/apache/spark/blob/094563384478a402c36415edf04ee7b884a34fc9/core/src/main/scala/org/apache/spark/scheduler/StageInfo.scala#L108  https://github.com/apache/spark/blob/78df2caec8c94c31e5c9ddc30ed8acb424084181/core/src/main/scala/org/apache/spark/scheduler/dynalloc/ExecutorMonitor.scala#L179 Pozdrawiam, Jacek Laskowski ---- https://about.me/JacekLaskowski "The Internals Of" Online Books <https://books.japila.pl/> Follow me on https://twitter.com/jaceklaskowski <https://twitter.com/jaceklaskowski> On Wed, Dec 30, 2020 at 3:34 PM Jacek Laskowski <ja...@japila.pl> wrote: > Hi, > > It's been a while. Glad to be back Sparkians! > > I've been exploring ExecutorMonitor.onJobStart in 3.0.1 and noticed that > it uses StageInfo.shuffleDepId  that is None by default and moreover > never "written to" according to IntelliJ IDEA. > > Is this the case and intentional? > > I'm wondering how much IDEA knows about codegen and that's where it's used > (?) > > I've just stumbled upon it and before I spend more time on this I thought > I'd ask (perhaps it's going to change in 3.1?). Help appreciated. > >  > https://github.com/apache/spark/blob/78df2caec8c94c31e5c9ddc30ed8acb424084181/core/src/main/scala/org/apache/spark/scheduler/dynalloc/ExecutorMonitor.scala#L179 > > Pozdrawiam, > Jacek Laskowski > ---- > https://about.me/JacekLaskowski > "The Internals Of" Online Books <https://books.japila.pl/> > Follow me on https://twitter.com/jaceklaskowski > > <https://twitter.com/jaceklaskowski> >