Erlang/Elixir and OTP
- 1. Erlang/Elixir and OTP Gil Meir, CTO, Spectory
- 2. Erlang • Erlang is a dynamically-typed, garbage-collected, concurrent, functional programming language that compiles to byte code and runs on a virtual machine • Created at Ericsson in 1986 and is completely open sourced (Apache v2) • Syntax is loosely based on Prolog
- 3. Erlang (cont.) • Share-nothing message passing (a.k.a Actor Model) • Light weight processes (a.k.a Green Threads) • Immutable Data Structures • Type annotations • Per Process Garbage Collector (soft real-time) • Hot code loading • Location transparency • Runtime system monitoring and observation • Built-in NoSQL database with ACID transactions
- 4. Open Telecom Platform • A set of design guidelines and libs for developing fault-tolerant, soft real-time, distributed systems • Battle tested for over 30 years in the Telecom industry and more recently at most of the leading Internet companies • Promotes a “let-it-crash” + “software watchdogs” approach for fault-tolerance, normalizes some aspects of Erlang
- 5. Why Elixir? • Modern Syntax • Unicode Strings • Fix Accidental Complexity (dict/orddict/gb_tree) • Meta-Programming, Protocols, Pipeline Operator, .. • Advanced tooling and interactive development • Superb web framework (Phoenix)
- 6. Some Fun with Elixir
- 7. More Fun with Elixir
- 9. OTP Concepts • Messages handled in order they are received to avoid message leak • Supervisor Trees – watchdogs for processes with multiple monitor and restart strategies • Well-defined sets of callbacks for processes that follow the same pattern (e.g GenServer implements start, init, handle_call, handle_cast, handle_info, code_change, …) • Applications – bundle modules, servers, supervisors and configs as a single logical unit (e.g. Logger, Db) • Release – A complete system of multiple applications bundled together under a version number with support for differential upgrades
- 10. Runtime Observer • Connect to remote system • View running processes • View process mailboxes • Trace messages • View Applications • View Supervision Trees • View Performance Metrics • View Logs • Restart Processes • View System Information
- 11. Phoenix Performance Language Framework Throughput (req/s) Go Gin 51,483 Elixir Phoenix 43,063 JavaScript (NodeJS) Express 9,966 Ruby Rails 3,275 • Benchmarks should never be taken too literally • Express Cluster and Rails5 make better use of multi-core CPUs and exhibit better throughput • YMMV
- 12. Elixir @ Spectory Websites and Webapps Mobile Backends IoT Backends Scripts Load Testers Web Scrapers Chat Servers (obviously) Jump in, the water’s fine