Erlang in Practice Episode 7: Writing Servers with gen_server

In the first half of this episode, we’ll learn how to write Erlang server processes using gen_server, a module in the OTP library. Then, in the second half of this episode, we’ll put what we learned into practice by incrementally refactoring two of our home-grown servers to use gen_server. As a result, you’ll be able to immediately apply gen_server to your next Erlang server process or one you’ve already written. You’ll learn how to:

• write a generic Erlang server process using gen_server
• design systems that decouple the message dispatch loop from the code that handles the messages for better reuse
• send RPC and cast-style messages
• initialize and shutdown gen_server processes
• scope the server to control who sees the server and who can send messages to it
• apply gen_server to a real-world problem
• refactor existing servers to use gen_server