Observer is a graphical tool for observing the characteristics of Erlang systems. Observer displays system information, application supervisor trees, process information, ETS tables, Mnesia tables and contains a front end for Erlang tracing.
As Elixir and Erlang both run on the same VM (Erlang VM or also known as BEAM), Observer can be run from either within Erlang shell or Elixir’s. The only tricky part is there’s a slight difference in the syntax on how to launch it.
Eshell V10.2 (abort with ^G) 1> observer:start(). ok 2>
Notice the period at the end of the command for Erlang.
iex(1)> :observer.start :ok iex(2)>
Please read the link provided below for more details and also on how to run Observer from a standalone node to minimize the impact of the system being observed.