Profiling memory usage in given process

A few things occur to me as to why that may be happening:

cast them out!

Are you using cast ?
We had an issue sometime ago where we were flooding a process with messages via cast, which caused its mailbox to grow indefinitely causing it to crash the BEAM VM.

queues

Using queues?
Queues that grow without boundary (looking at you hackney) misbehave spectacularly, consuming all the system’s memory until a crash is inevitable.

Tools you can use

If you want a specific tool, then I know of erlyberly, which shows you memory and messages passed between processes.

You can also find other tools in this discussion:

I already solved the issue as in why and what is happening. It was this bug in absinthe we stumbled upon: Obscenely high memory usage with deeply nested inputs during Absinthe.Blueprint.Transform.walk · Issue #569 · absinthe-graphql/absinthe · GitHub

I’d like to know if there’s something that’ll help me out next time tracking down such and similar issues

I had a look at recon v2.5.3 — Documentation and Erlang’s internal tools but I don’t think there’s anything that will allow me to just have a glance at the memory and figure out what exactly eats it up…

How ‘exactly’ do you want it? :etop.start() is pretty useful (make sure to use a new console) or observer.

As for what is on the stack… unsure…

That can come in handy although I don’t think it actually does what I want. I think you can do similar thing from observer if you sort processes by memory, but this is cool to have this in case Erlang on the server has no X support.

You can run observer locally and connect to a remote node to view its information. Here’s a blog post about it: Using Erlang Observer on a Remote Elixir Server - Josh Bavari's Thoughts

Alternatively, have a look at observer cli. Its a terminal version of observer which is fantastic when no X is available (and actually for many cases I prefer its interface over the graphical observer anyways).

But to respond to both of you and @axelson, this won’t help me when I precisely know which process is consuming the memory? I would like to know what is consuming the memory, and unless I am missing some functionality, observer does not allow me to have insignt into what’s in the memory itself

:etop does tell you about the memory consumption of a process.

Problem though: If it is not the processes heap + stack but some references to the bin-heap, then you are lost. Space-Leaks on the bin heap are hard to debug due to its ref-counting nature. And even a single "a" which was produced by slicing into the gigabyte of JSON file can cause keeping the full JSON forever!

Do you mean that etop gives me insight into memory consumption of the process (which it does) or can I also get insight into what consumes the memory? I can’t find the later