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@josevalim
Created Aug 27, 2014
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What would you like to do?
+ EPMD
- Distributed systems are cool
- Distributed systems are also complex
- First step: How to find other machines (and nodes) in the same network
- Erlang Port Mapper Daemon
+ EPMD in C
- Ships with Erlang
- is a TCP server
- usually 4369
- binary protocol
- stateful
- replaceable
+ ExPMD
- EPMD written in Elixir
- Pattern matching on binary strings
- Still getting used with immutability
- Using agents to keep data
+ Requests ()
- Alive -- Sent by new node on start-up
Registers named node and port (etc) on local EPMD
Connection remains open until node exits.
- Port -- Receives a node name
Returns port registered with given name
- Names -- return list of all registered names/ports
- wireshark
+ Live demo
- iex --name sophia (alive)
- Node.ping(:"jv@jv.hackerschool.com")
- finds EPMD at jv.hackerschool.com
- asks for node named jv
- :net_adm.names()
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