💧 Elixir Advanced

What are Elixir's process monitoring, tracing, and debugging tools?

Answer

Elixir's BEAM VM provides exceptional introspection and debugging tools. Observer: :observer.start() launches a GUI showing process list, supervision tree, ETS tables, memory usage, and message queues. :sys module: get/replace GenServer state: :sys.get_state(pid). Trace process: :sys.trace(pid, true). :dbg module: trace function calls across all processes: :dbg.tracer(); :dbg.p(pid, :all); :dbg.tpl(MyModule, :my_function, :x). Recon: production-safe process introspection library. :erlang.process_info: get process details (mailbox length, memory, reductions, backtrace). Telemetry: structured event system for metrics collection (used by Phoenix, Ecto, Broadway). AppSignal, Datadog: APM with BEAM-aware agents. Livebook: interactive notebooks for exploring running applications. Unlike most languages, BEAM's introspection works on running production systems without restarting — you can attach a console (iex --remsh) to a production node and inspect state live.