Scala ecosystem

Transcript

1. Scala ecosystem Demystifying @jeduardocosta
2. Agenda - The Scala language - Lightbend and community - SBT and tools - Web development - Database libraries - Akka Toolkit - Extending Functional Programming - Dependency Injection - Other usages (machine learning..) - The future... - How could I learn more?
3. The Scala Language
4. The Scala Language - Martin Odersky - Released on 2004 - EPFL background (École Polytechnique Fédérale de Lausanne) - Statically typed - Hybrid language (OOP and FP) - JVM based - Fully interoperable with Java
5. Language versions - 2.0 until 2.90 (mar/2006 - may/2011) - 2.10 (may/11) - 2.11 (apr/14) - 2.12 (nov/16) - 2.12.4 (out/17) and last version - Binary compatibility - 2.12.0 -> 2.12.4 - Upgrading from 2.10.x -> 2.11.x -> 2.12.x
6. Lightbend
7. Lightbend - Founded in 2011 - Formerly know as Typesafe (changed in fev/16) - It provides open-source and enterprise platform for build reactive applications
8. Lightbend
9. Reactive Streams - Main contributors of Reactive Streams - Provide a standard for asynchronous stream processing with non-blocking back pressure
10. Reactive Streams - Main contributors of Reactive Streams - Provide a standard for asynchronous stream processing with non-blocking back pressure - JDK9 (released in set/2017)
11. Reactive Streams - Reactive Streams Specification for the JVM https://github.com/reactive-streams/reactive-streams-jvm
12. Reactive Manifesto
13. Reactive Manifesto - Responds in a timely manner if at all possible - Stays responsive in the face of failure - Stays responsive under varying workload - Works with asynchronous messaging to establish a boundary between components that ensures loose coupling, isolation and location transparency
14. Reactive Manifesto - In the launch
15. SBT and tools
16. SBT and tools - A simple build tool - Ivy dependency management - Set tasks and then run them in parallel from the shell - Custom plugins (native packager etc) - Natural choice for Scala language, as well Leiningen for Clojure or Gradle for Android
17. SBT and tools - SBT 1.0 (released on ago/2017) - Required Scala 2.12.x - Zinc 1, a faster incremental compiler
18. Web development
19. Web development
20. Play framework - Web framework - Java and Scala - Modern web and mobile - Template engine - Support for internationalization - Uses dependency injection pattern - A complete web framework (like Rails!) - https://github.com/playframework/playframework
21. Akka Http - It's general toolkit for providing and consuming HTTP-based services - HTTP stack on top of akka-actor and akka-stream - Streaming-first - Routing DSL - Directives - https://github.com/akka/akka-http
22. Scalatra - Micro-framework - Sinatra-like - Quickly build high-performance websites and APIs - Template engine - Authentication, CORS, internalization - https://github.com/scalatra/scalatra
23. Finagle - Created by Twitter - Finagle is an extensible RPC system for the JVM - Protocol-agnostic system - Finagle implementations (binary parsers, http2, memcached, thrift, oauth2, postgres, websockets) - https://github.com/twitter/finagle
24. Finatra - Scala applications on top of TwitterServer and Finagle - Production use of Twitter - Support for HTTP & Thrift - https://github.com/twitter/finatra
25. Lagom framework - Reactive systems - Java and Scala - Highly opinionated framework - Built on Akka and Play - CQRS and Event Sourcing support - Message Broker support - Service locator support - Embedded Cassandra and Kafka
26. Database libraries
27. Database libraries
28. Slick - Like ORM, but it's not ORM - Data persistence (functional relational mapper) - Plain SQL queries - Requires boilerplate - Support for DB2, JavaDB, H2, HyperSQL, MSAccess, SQL Server, MySQL, Oracle, PostgreSQL and SQLite databases - https://github.com/slick/slick
29. Quill - Compile-time language integrated queries and validation - Boilerplate-free mapping - Support for MySQL, PostgreSQL, SQLite, H2 and SQLServer database
30. Quill
31. Akka Toolkit
32. Akka Toolkit - Java and Scala - Actors model - Up to 50 million msg/sec on a single machine - ~2.5 million actors per GB of heap - Networking (clustering) - HTTP - Streams - Alpakka - Persistance
33. Extending Functional Programming
35. Cats - Provide abstractions for functional programming - Used by several libraries for Scala - Better documentation than your competitor (ScalaZ) - Functor, monads, variance - https://github.com/typelevel/cats
36. Cats - Easy and Efficient Data Validation with Cats – Daniela Sfregola - https://www.youtube.com/watch?v=OkTfcyFohS0
37. Dependency Injection
38. Dependency Injection - Cake Pattern - Monad Reader - Or we could use some library to do that - MacWire - Guice
39. Other usages
40. Scala.js - A safer way to build robust front-end web applications - Incremental compilation guarantees speedy (1-2s) - Interoperability (React, Angular etc) - Go beyond JavaScript ES6, today
41. Kamon - Metric recording and trace manipulation - Metrics collection - Akka, Scala Futures, Play framework, JDBC, System Metrics - Reporter backends - StatsD, NewRelic, Datadog, FluentD, JMX, InfluxDB
42. Kamon + Akka Actors + Datadog
43. Kamon + Akka Actors + Datadog
44. Machine Learning
45. The Future...
46. Dotty - A next generation compiler for Scala - The focus in mainly on simplification - Currently in development - http://dotty.epfl.ch/
47. Dotty
48. Scala Native - Optimizing ahead-of-time compiler - Lightweight managed runtime - Cross-publishing infrastructure against JVM, JS and Native platforms - https://github.com/scala-native/scala-native
49. How could I learn more?
50. Next steps - Meetup Scaladores - Scala Days conferences - Weekly Scala newspaper ( http://scalatimes.com/ ) - Coursera.org - Scala courses - The Neophyte's Guide to Scala