I'm surprised to hear that throwing an exception there causes any havoc; in the code there is a generic exception handler that shouldn't let any uncaught exceptions leak through. There is potential for trouble, though, if you are using a spawner that does some vial initialization during the start() call, such that calling stop() or start_polling() throws an exception if start() was not previously called. If that is what's happening, it would be a bug in the spawner class and you would want to file an issue with the corresponding project.
Michael On Fri, Jan 19, 2018 at 12:51 PM, Tim Harsch <harschw...@gmail.com> wrote: > Thank you Michael, that is very helpful. In this case I am using > pre_spawn_hook, in lieu of a spawner options form. So I think the > exceptions are causing havoc to the server. > I went the route of the pre_spawn_hook because in my case because the user > doesn't need to inform the hub of the docker image, it can be done in the > hook. But that's where an issue could arise.. and I'm not sure to handle > it gracefully. > > Tim > > > On Friday, January 19, 2018 at 9:44:34 AM UTC-8, Michael Milligan wrote: >> >> Hi, >> >> The Spawner's start() function is called unconditionally after >> pre_spawn_hook() returns, so you're correct that the return value will have >> no effect. However, if you raise an exception, it will be caught by the app >> and the associated error message will be logged. There are some cases where >> exception error messages are displayed to the user. If I'm correctly >> interpreting the code, in this case a message will be displayed *if* you >> have a spawner options form set up. >> >> Michael >> >> On Fri, Jan 19, 2018 at 11:06 AM, Tim Harsch <harsc...@gmail.com> wrote: >> >>> Hi all, >>> Is there a way in the pre_spawn_hook I could invalidate the spawn? >>> return True/False doesn't work. I'd like it to ultimately produce a user >>> friendly result to the user if an issue occurs >>> >>> Thanks, >>> Tim >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Project Jupyter" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to jupyter+u...@googlegroups.com. >>> To post to this group, send email to jup...@googlegroups.com. >>> To view this discussion on the web visit https://groups.google.com/d/ms >>> gid/jupyter/97c1bbb1-ada9-44b0-ad68-aff8b1181e94%40googlegroups.com >>> <https://groups.google.com/d/msgid/jupyter/97c1bbb1-ada9-44b0-ad68-aff8b1181e94%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Michael Milligan, Ph.D. | Supercomputing Institute >> Assistant Director for | University of Minnesota >> Application Development | mill...@umn.edu >> www.msi.umn.edu/staff/milligan | Phone: 612-624-8857 <(612)%20624-8857> >> > -- > You received this message because you are subscribed to the Google Groups > "Project Jupyter" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to jupyter+unsubscr...@googlegroups.com. > To post to this group, send email to jupyter@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/jupyter/8cece011-11eb-4053-86e0-13ca6a0c8cd6%40googlegroups.com > <https://groups.google.com/d/msgid/jupyter/8cece011-11eb-4053-86e0-13ca6a0c8cd6%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Michael Milligan, Ph.D. | Supercomputing Institute Assistant Director for | University of Minnesota Application Development | milli...@umn.edu www.msi.umn.edu/staff/milligan | Phone: 612-624-8857 -- You received this message because you are subscribed to the Google Groups "Project Jupyter" group. To unsubscribe from this group and stop receiving emails from it, send an email to jupyter+unsubscr...@googlegroups.com. To post to this group, send email to jupyter@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jupyter/CAPuy8goJNim%3DFRC-u2tGCvO6fmV3YsXzgBUKXDxL2Op_EmsrNA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
