Out of memory (OOM) warnings - is it possible?

[joepio]

Recently, my actix-web powered server crashed without any errors or warnings. I tried various RUST_LOG settings, tracing parameters, but I wasn't able to find why my server stopped.

With the help of robjtede (thanks again) I ran dmesg, which told me:

[44807566.669609] Out of memory: Killed process 3595263 (atomic-server) total-vm:652248kB, anon-rss:164276kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:588kB oom_score_adj:0

Probably mostly my bad for running my server on a machine with 512 MB ram, but still, I feel like this type of error should be more manageable, perhaps with:

• Emit warnings when you're close to out of memory
• Panic / Error when out of memory

There's std::alloc::set_alloc_error_hook (nightly only as of now).

I'm not sure whether this should be an Actix thing, or a Tokio thing, or neither - perhaps the library user of Actix should deal with this.