Background

I have an app that checks the machine’s memory usage using :memsup.get_memory_data/0 before proceeding with an operation. If said memory usage is too high, I just refuse to do the operation.

Problem

Now, according to the documentation, :memsup.get_memory_data asks the machine how much memory it has allocated every X time. By default X is 60 minutes. This is wwaaaayyy too long.

There is a way to configure it using :memsup.set_check_interval/1 but the new interval I pass only takes effect after the first check, so it means that if I start the app and then use :memsup.set_check_interval(1) to check the memory every minute, I will have to wait 60 minutes before I start checking the memory every minute like I want. What’s even worst, is that if the application or process is restarted, I go back to waiting 60 minutes again because any changes using this function are not persisted.

Code

So in order to use :memsup you need to include os_mon into your extra_applications mix.exs file:

  def application do
    [
      extra_applications: [:logger, :runtime_tools, :os_mon],
      mod: {MyApp.Application, []}
    ]
  end

However, this doesn’t tell me how I can configure the os_mon app, and reading the erlang documentation lead me to this config page which only confused me further.

I was hopping to see something simple, like changing my config.exs file but I found no information regarding it.

Question

How do I configure os_mon on startup, so its memory check interval is 1 minute instead of 60?