QlikView Distribution Service - orphaned qvb.exe's
We had a problem recently in one of our QlikView environments where the Tasks (in QMC) would appear to be running but not actually doing anything. By looking at Task Manager on our Publisher server I quickly found that there were 10+ qvb.exe's although there was only one task running in QMC. We stopped / started QlikView Distribution Service causing these orphaned qvb.exe's to be killed and then the genuine jobs could run as they were no-longer waiting behind a stuck queue.
We have 10 "Max number of simultaneous QlikView engines for distribution".
Has anyone else experienced similar issues? Does anyone know why qvb.exe's are likely to become orphaned? Other than regular restarts of QlikView Distribution Service is there anyway to prevent this happening again?
We will be raising a case with Qlik but I've always found the community a better resource so I'm asking here.