This has turned out to be an interesting conversation. Thanks, everyone! William, I love your pathological case. You're right, of course. I think I am lumping all situations where you need to kill the tab as basically on the same tier of user irritation.
On Wed, Sep 4, 2019 at 12:25 AM Pete Blois <[email protected]> wrote: > As a maintainer of quite of bit of Colab's iframing infrastructure: it > does a good job of isolating for security but it's not great at preventing > the `while (true) {}` case. The reason is that if the iframe is just a > srcdoc iframe then it shares the same thread, so a hang there will still > hang your entire page. If the iframe is using a separate origin then with > Chrome's OOPIF > <https://www.chromium.org/developers/design-documents/oop-iframes> > feature it will wedge all iframes across all tabs, in even worse ways. > OOPIF's are still pretty new. Today, when dealing with while (true), the > non-iframed error model is superior. > > I'm a strong believer in the value of the security model offered by > iframes, but they are non-trivial to implement. > > try opening a notebook with 500 visible cells with output in Colab, and >> watch things die badly, due to trying to create 500 nontrivial iframes. > > Yeah, there are a number of tricks... If the 500 cells were generated by > Colab then the resulting height of the output is also written to the > notebook file so a placeholder can be rendered instead. Then > IntersectionObserver is used to only render the output when it becomes > visible. This also helps minimize resize jank when loading a large > notebook. 500 cells is still... a whole lot of cells. > > On Tue, Sep 3, 2019 at 1:12 PM 'Aaron Watters' via Project Jupyter < > [email protected]> wrote: > >> Thanks Darian, >> >> I'm concerned that there is precisely one Javascript thread shared by all >> notebook interfaces in Jupyter Lab. >> I will try to come up with an example involving animation running in >> multiple notebooks that causes performance degradation. >> >> I agree that iframes are difficult to deal with. I think the additional >> robustness might be worth it. Regarding your specific objections: >> >> 1) dropping "dead zone" -- this may be -- I don't know. I'm personally >> probably willing to sacrifice this use case. I never "drop" anything into >> a notebook myself. >> 2) iframes can't communicate with the rest of the application -- I think >> you could mediate communication between iframes if necessary on the server >> side. >> >> Thanks for the reply and comments! -- Aaron Watters >> >> On Tuesday, September 3, 2019 at 3:19:31 PM UTC-4, Afshin T. Darian wrote: >>> >>> Hi Aaron, >>> >>> Thanks for writing. If you have a test case that you can contrive to >>> crash JupyterLab, we'd love to try to address the issue head on. >>> >>> But in the absence of that, here's what I surmise would happen if you >>> did run into a notebook that causes a runaway JS thread to cause JupyterLab >>> to become unresponsive: >>> >>> 1. Let's say you execute a cell and its result is that the web app >>> becomes unresponsive. >>> 2. Like many web apps, you would either refresh the tab or you would >>> close it and open a new one. >>> 3. When the new tab opens, it would restore the state of JupyterLab to >>> the last known saved state. >>> 4. Your broken notebook would be open and you could either close it or >>> modify the contents of the offending cell. >>> >>> I think you'd basically be in the same situation you were in the classic >>> notebook because of JupyterLab's layout/state restoration. >>> >>> As far as using iframes, they bring with them a lot of trouble, which >>> makes them unsuitable for an application like JupyterLab. They become a >>> "dead zone" in terms of drag and drop interoperability with the rest of >>> what is on your screen. Also, they don't have programmatic access to the >>> rest of the JupyterLab application and it makes interacting with other >>> extensions quite difficult. >>> >>> Thanks again for reaching out. If you do have a test notebook you'd like >>> us to look at, please reach out again or please file an issue >>> https://github.com/jupyterlab/jupyterlab/issues/ so we can track it! >>> >>> Cheers! >>> >>> -Darian >>> >>> On Tue, Sep 3, 2019 at 8:17 PM Jason Grout <[email protected]> wrote: >>> >>>> Thanks for commenting on this! Do you want to open an issue on the >>>> JupyterLab repo about this where we can discuss more in detail the >>>> implications? >>>> >>>> For example, someone could write a notebook opener that would use >>>> iframes for isolation and would work alongside everything else in jlab. >>>> That might be a really interesting extension idea to explore. >>>> >>>> Thanks, >>>> >>>> Jason >>>> >>>> >>>> On Tue, Sep 3, 2019 at 12:09 PM 'Aaron Watters' via Project Jupyter < >>>> [email protected]> wrote: >>>> >>>>> I have reservations about Jupyter lab and I don't want to see "classic >>>>> notebooks" going away primarily for the following reason: >>>>> >>>>> My strongest attraction to Jupyter is that it provides a platform for >>>>> combining the Python interpreter with Javascript based tools >>>>> and visualizations. For that reason I want to use and develop lots of >>>>> Javascript for use inside Jupyter. >>>>> >>>>> If in "classic" notebook the javascript interpreter falls in to an >>>>> infinite loop or has a memory leak or some other performance issue... >>>>> just close the browser tab. Other notebooks are usually unaffected. >>>>> Nice! >>>>> >>>>> If in the Jupyter lab interface the javascript interpreter falls in >>>>> to an infinite loop or has a memory leak or some other performance >>>>> issue... >>>>> all the notebooks and other features in the Jupyter Lab interface stop >>>>> working. Not nice. >>>>> >>>>> It might be possible to make the lab interface as robust as "classic" >>>>> if Jupyter lab embedded each notebook in an iframe with an independent web >>>>> context. >>>>> I'm unsure of the details of managing iframes or other implications. >>>>> >>>>> I think that this is the approach adopted by google colaboratory for >>>>> example https://colab.research.google.com/notebooks/welcome.ipynb >>>>> >>>>> Thanks to everyone for all the great work on Jupyter related projects >>>>> -- I just needed to get this comment off my chest. >>>>> Please comment or correct me. >>>>> >>>>> -- Aaron Watters >>>>> >>>>> -- >>>>> 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 [email protected]. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/jupyter/f625f4c4-1ea5-48a6-853c-89afd09ac2d6%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/jupyter/f625f4c4-1ea5-48a6-853c-89afd09ac2d6%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> 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 [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/jupyter/CAPDWZHz%3DQOh_E_RwuobM9Ye3zGNQ2QMi3UmYM1HD3PW_REKZfQ%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/jupyter/CAPDWZHz%3DQOh_E_RwuobM9Ye3zGNQ2QMi3UmYM1HD3PW_REKZfQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> 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 [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/jupyter/39b73eb6-0b13-480b-b643-a53edd334118%40googlegroups.com >> <https://groups.google.com/d/msgid/jupyter/39b73eb6-0b13-480b-b643-a53edd334118%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jupyter/CACvpcBEddR47TCUJh1PjGZnTntvKLsbr8tX1KH2_d0%2BtYYXFjw%40mail.gmail.com > <https://groups.google.com/d/msgid/jupyter/CACvpcBEddR47TCUJh1PjGZnTntvKLsbr8tX1KH2_d0%2BtYYXFjw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Project Jupyter" group. 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