limited environments run into deno memory issues

[cscheid]

Some part of v8's startup process mmaps an 8GB chunk of memory. We need to allow users to configure that.

[statik]

thank you!

[cscheid]

@statik I just asked the deno folks during deno office hours, and unfortunately they didn't have a ready answer for me. The best advice they had was for us to look at the v8 flags available. I went over them (there's 500+) and I couldn't find anything that jumped at me. I'll follow up with you directly for next steps.

[statik]

@cscheid thank you!

[lachlansimpson]

Seen in Posit's internal customer ticket 88813. Reporting that, within Posit Workbench,

when setting max-memory-mb =7000 (which is not a ridicul amount), we can't launch any quarto

[cscheid]

Hey @datakid - can you add some context to your message for the non-posit folks that read this repo? Thanks!

[VincentGuyader]

Hey @datakid - can you add some context to your message for the non-posit folks that read this repo? Thanks!

I'am the "Posit's internal customer ticket" author :)

In posit workbench, I can choose to restrict the RAM available to users. This is done in the /etc/rstudio/profile file. (see : https://docs.posit.co/ide/server-pro/latest/rstudio_pro_sessions/user_and_group_profiles.html)

On shared servers, even powerful ones, we will often restrict the ram to allow everyone to work properly.

Here if I put less than 8Gb of ram each, the users can't initiate a quarto anymore...

[cscheid]

@VincentGuyader got it. Unfortunately I haven't been able to figure out the v8 option to reduce the amount of address space it requests. I can see through a profile that it never actually allocates that much ram. The strace log shows a call to mmap that "sets aside" 8GB of virtual memory addressing, but doesn't actually allocate it. In our experience, the latest version quarto doesn't allocate more than ~1.5GB of RAM. Is it possible to configure different rules for different processes?

[tnederlof]

A Posit Workbench customer also encountered this on one of their QA servers where the user profile was set below 8gb and were getting v8 errors in the terminal. Setting the limit > 8gb fixed it.