the default fly.io deployment should at least have 512mb

[tcoopman]

If you don't have a deployment of 512mb you can't for example do a Mix.install of req.
The livebook gives a connection error, but it's not clear what happened (until you get an email from fly.io about the memory).
As a first experience, this isn't great.

[josevalim]

One idea is to change the notebook URL when installing. Then, if we rejoin the app, we can’t find the session, no session exists and the params is set, it means it rebooted and we can show the message. If we want even more precision, we can store when installation started, when the app booted and check they happened within X seconds.

[josevalim]

The message would say installation failed and one possible reason is lack of memory. We can also give a unique ID to each node and make it the first 8 characters of the session or part of the install parameter. So we only show the warning if the node changed.

[tcoopman]

I'm not entirely sure what you're suggesting :-) but a better error/warning message would already help a lot.

But if most things you do with a livebook are going to fail because of memory, shouldn't a bit more memory be part of the default install on fly. (I guess they don't do it, because 512mb is not part of the free tier anymore).

[josevalim]

The goal is to improve the error message and earlier feedback. The issue is that compiling code is costly and I suspect moving to 512GB is just slightly postponing the issue. :)