Netty training
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This document provides an overview of Netty, an asynchronous event-driven network application framework for Java. It discusses key Netty concepts like the event loop, channels, pipelines and handlers. It also provides examples of building an echo server and client with Netty. Additionally, it mentions several large companies that use Netty in production and open-source projects built with Netty. Finally, it discusses some alternative solutions to Netty like ServiceTalk, Armeria and Reactor Netty that provide additional features on top of the Netty core.
Netty training
- 2. About me ❏ Software Architect at ilegra ❏ AWS & GCP ❏ Google Cloud Architect Certified ❏ Microservices / DevOPS ❏ Mortal Kombat Player :D ❏ https://github.com/marceloserpa/ ❏ https://www.linkedin.com/in/marceloserpa/
- 3. About me ❏ Father ❏ Software Architect at ilegra ❏ Devops Engineer Specialist ❏ Google Cloud Architect Certified ❏ SOA Specialist ❏ Football fun ❏ Github ❏ Twitter ❏ Blog
- 4. Exercise 1 ● Create a TCP server using socket API. Use the template available here. ● It needs to be able to process more than one request at time (use threads)
- 5. Let's review what we did and think about It
- 6. How works the traditional way ● thread per request model ● One thread for the entire request flow ● limitations 1 thread == 1MB (around it)
- 7. Blocking and synchronous ● Sequential ● Unnecessary waiting time ● Total time is high
- 8. Expectations for modern applications ● high throughput ● scalability ● lower cost (BE CAREFUL)
- 9. Java NIO ● Java abstraction to deal with low level I/O ● Work on top of channels and selectors (scales better) ● Is much more efficient than native sockets and easier to deal with.
- 10. Java NIO - Can become complex as well - link
- 11. Networking programing ● Is inhirintanly complex ○ It’s more than programming languages or algorithms ○ Requires specific skills ○ Network programs have their own performance requirements ○ Needs to be efficient, otherwise they won't attend the current market requirements.
- 12. What is Netty “Netty is a NIO client server framework which enables quick and easy development of network applications such as protocol servers and clients. It greatly simplifies and streamlines network programming such as TCP and UDP socket server.” ● A networking programming server ● open source and written in Java ● Asynchronous and event driven ● Enforces a better design. Decouples business logic from network programming details. ● Configurable ● Extensible
- 13. Companies using Netty ● Apple ● Twitter ○ using Finagle their Netty-basead framework in inter-system communication ● Facebook ○ uses Netty in Nifty - Thrift service ● Google ● Square ● Instagram ● Netflix
- 14. Companies using Netty - Netflix
- 15. Companies using Netty - Twitter
- 16. OSS project using Netty ● Infinispan ● HornetQ ● Vert.x ● Apache Cassandra ● ElasticSearch
- 17. Cassandra - More nodes, worst the performance
- 18. Cassandra - Streaming data between nodes - Before
- 19. Cassandra - Streaming data between nodes
- 20. Cassandra - Streaming data between nodes - Before
- 21. Cassandra - Streaming data between nodes - Before
- 22. Cassandra - Streaming data between nodes - Before
- 23. Cassandra - Streaming data between nodes - Now
- 24. Cassandra - Streaming data between nodes - Now
- 25. Startups using Netty ● Firebase ● Urban Airship
- 26. Non-Blocking and asynchronous ● Initialize something now ● Using Threads Efficiently ● Scalability ● More efficient (doing more with less resources) ● concurrency
- 27. Core components ● EventLoop ● Channel ● Callback ● Future ● Event Handler
- 28. Netty - High level arch
- 30. Echo Server Example Eventloop impl in use. There are others...
- 31. Echo Server Example Utility that helps glue all pieces
- 32. Echo Server Example Transport type defined for the channel
- 33. Echo Server Example Setting handler on the pipeline chain
- 34. Echo Server Example Bind the server and channel and wait this process complete
- 35. Echo Server Example Block the current thread and wait until the channel is closed
- 36. Echo Client - Example
- 37. Echo Client - Example
- 38. What is EventLoop? How it works? ● Threading model ● Control flow ● Dispatching events to ChannelHandlers
- 39. EventLoop -Task Scheduling - run later scheduling task to run after 10 seconds
- 40. EventLoop -Task Scheduling - periodically scheduling task to run every 10 seconds staring in 10 seconds
- 41. What is EventLoop group? ● Allocate EventLoop for a Channel ● Uses round-robin to distribute load ● An application needs a least 1 EventLoopGroup
- 42. Channel ● Socket ● Receive events ● Transport layer ● Notify Channel Handlers
- 43. ChannelHandler ● Decoupled business from networking ● Implements the logic ● React to event notification ● ChannelInboundHandlerAdapter ○ channelRead() ○ channelReadComplete() ○ exceptionCaught() ● ChannelHandler are invoke for different events ● Hook lifecycle
- 44. ChannelPipeline ● chain of ChannelHandler ● propagation flow ● order to execute channel handlers ● ChannelHandler is installed as follow: ○ a Channelnitializaer is registered to server bootstrap ○ when Channelnitializaer.init() is called it install the channels handlers in the pipeline
- 45. Bootstraper for clients (Bootstrap) ● establish connection ● connect to remote peer ● requires only one EventLoopGroup for servers (ServerBootstrap) ● listening to income connections ● requires two EventLoopGroup: ○ one for ServerChannel ○ others to registered all channel that you want
- 46. Bytebuf ● Byte container ● Alternative for NIO ByteBuffer ● Used to data
- 47. Codecs ● Transforms streams of byte from one format to another Encoder Decoder
- 48. Codec Example - Bootstrap Creating a ServerBootstrap and registered EventLoopGroup
- 49. Codec Example - Bootstrap Registered Initializer to configure Pipeline
- 50. Codec Example Registered codecs and aggregator on ChannelPipeline
- 51. Codec Example - Handler part 1 Use decoder to extract parameters
- 52. Codec Example - Handler part 1 Call service to handle business rules
- 53. Codec Example - Handler part 2
- 54. Solution based Netty - ServiceTalk https://github.com/diegopacheco/java-pocs/tree/master/pocs/servicetalk-fun
- 55. Solution based Netty - ServiceTalk ● gRPC ● HTTP/2 ● Long-polling ● Smart Client ○ Client side load balancing ○ retry ● Modularization ○ use just you need
- 56. Solution based Netty - Armeria https://github.com/diegopacheco/java-pocs/tree/master/pocs/armerica-fun/src/main/java
- 57. Solution based Netty - Armeria ● HTTP/2 ● Integration with gRPC and Thrift ● Metrics ● Circuit breaker ● Client-side health-check, retries and client side load balancing ● Distributed Tracing with Zipkin ● Service discovery (DNS and Zookeeper) ● Built on top of Reactive Streams and Java 8 CompletableFuture
- 58. Solution based Netty - Reactor Netty https://github.com/diegopacheco/java-pocs/tree/master/pocs/reactor-netty-simple
- 59. Solution based Netty - Reactor Netty ● Support reactive streams specification ● HTTP, UDP and TCP ● Schedulers ● Parallel Flux
- 60. Performance/Scalability > Developer Experience ● Number of lines of code is not a problem ● IFs (if not shells) is not a problem ● You don't deal with this code everyday ● There are books and materials on the web (stack overflow, etc...) ● Less lines of code does not means is better ● Spring might be “feeling” better but has worst performances and more deps ● Developers should care more about the business ○ User Experience -> slow server ○ Cost Reduction -> doing more with less(less cpu and memory used - more toughtput) ○ Reliability -> netty is battle tested by Silicon valley biggest IT companies in the world.
- 61. Netty Thank you!
- 62. Exercise 2 ● Change the code made on exercise 1, this time using Netty as a a server implementation and client. ● Use this template in order to get started.
- 63. Exercise 3 ● For this exercise we are gonna use same problem as described on exercise 2, but this time using an http interface rather than exposing an TCP socket. ● Server should be called like this: localhost:8080/training/netty/sum?num1=1&num2=4 ● Use this template in order to get started.
- 64. Exercise 4 ● Do the same implementation of exercise 3 using ServiceTalk with JaxRS ● Use this template in order to get started.