Erlang distribution

Backs Act 1: what actually happens when two BEAM nodes connect.

Questions to answer

• What does EPMD store, what port does it listen on, and what does a node ask it?
• The handshake step by step: name exchange, challenge, cookie digest. Which version of the handshake does current OTP use?
• What runs over the connection once it is up — the control message types behind send, link, monitor, spawn.
• Heartbeats: net_ticktime, and how long a dead node goes unnoticed by default.
• Full mesh: why connecting to one node connects you to all of them, and what that costs as the cluster grows.
• What replaces EPMD when you don’t want it (-start_epmd false, -erl_epmd_port, custom epmd_module).

Where the evidence lives

• OTP source: otp/lib/kernel/src/net_kernel.erl, otp/lib/kernel/src/dist_util.erl, otp/erts/epmd/src/. Pin the OTP tag when citing lines.
• The wire capture in Experiments.
• The Erlang distribution protocol docs — add to Sources when read.