stefanchrobot
I’ve been looking at my application in terms of resource usage. It’s a simple SQS consumer that calls some APIs and is under a very small load. BEAM constantly reports usage of around 70MB of memory:
I’m not sure what to think about it. Honestly, I expected a smaller footprint. I’m running with the default settings and simple MIX_ENV=prod mix run.
Is there an easy way to shave off some memory? Also, I’m wondering - why so many atoms are used?
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jeremyjh
Each module, and every function in every module is an atom. If you are loading a few libraries hitting 22K isn’t too hard. I’m not sure what to think of the memory. Its not so bad compared to other high-level language VMs though is it? I’m sure Go or Rust would be a lot smaller but a better comparison is Ruby, Python or Java.
jeramyRR
70 MBs seems a bit high for a small app. What all libs are you loading?
The image below shows a basic Phoenix app.
jola
If you do try building a release, I’m curious to see what the memory usage turns out to be. I made a quick comparison in a project of my own and also just a plain new phoenix project, in both cases memory use was much higher in the release. Why do releases use so much more memory than `mix run`? - #2 by michalmuskala
As I point out though, my comparison may be unfair, as not all code is necessarily loaded in the
mixversion when I checked memory use, while releases preload all modules. But you should be able to get an accurate comparison.