Netty - Montreal Java User Group 2024-05-21

Netty
Montreal Java User Group
2024-05-21

Transcript

1. Netty Montreal Java User Group Sean Sullivan May 21, 2024
2. Agenda 📍 About me 📍 Netty project 📍 Netty in action
3. About me Portland Oregon Java since 1996 open source contributor
4. Netty contributor
5. ✅ async-http-client ✅ reactor-netty ✅ Netflix Zuul ✅ Apache Pinot
6. Netty is open source
7. Netty at Netflix Netty Zuul AWS Cassandra Netty
8. Zuul is built on Netty
9. Zuul: Server.java
10. Zuul server channel initializer
11. Zuul channel handlers
12. Zuul: close on idle handler
13. Zuul: close on idle handler
14. Zuul push messaging
15. Zuul push messaging
16. Zuul: sendPushMessage
17. Let’s talk about Cassandra
18. Cassandra is built on Netty
19. Cassandra: SocketFactory.java
20. “Netty is an asynchronous event-driven network application framework”
21. 📍 Apache ActiveMQ Artemis 📍 Apache Bookkeeper 📍 Apache Camel 📍 Apache Cassandra 📍 Apache CXF 📍 Apache Druid
22. 📍 Apache Flink 📍 Apache NiFi 📍 Apache Pinot 📍 Apache Pulsar 📍 Apache Spark 📍 Apache Zookeeper
23. 📍 Armeria 📍 Micronaut 📍 Netflix Zuul 📍 OpenSearch
24. And many others… 📍 Apple Servicetalk 📍 Azure SDK for Java 📍 AWS SDK for Java (v2) 📍 async-http-client 📍 grpc-java 📍 Expedia Styx 📍 Play Framework 📍 reactor-netty 📍 vert.x 📍 gatling
25. why is Netty popular?
26. blocking I/O non blocking I/O
27. JDK 1.0 socket API
28. JDK NIO
30. Netty core concepts ✅ io.netty.channel.Channel A nexus to a network socket or a component which is capable of I/O operations such as read, write, connect, and bind
31. Netty core concepts ✅ io.netty.channel.ChannelPipeline A list of ChannelHandlers which handles or intercepts inbound events and outbound operations of a Channel
32. Netty core concepts ✅ io.netty.channel.ChannelHandler Handles an I/O event or intercepts an I/O operation, and forwards it to its next handler in its ChannelPipeline
33. Netty core concepts ✅ io.netty.buffer.ByteBuf A random and sequential accessible sequence of zero or more bytes
34. High performance buffer pool Netty 4 introduces a high-performance buffer pool which is a variant of jemalloc https://netty.io/wiki/new-and-noteworthy-in-4.0.html
35. High performance buffer pool ✅ Reduced GC pressure incurred by frequent allocation and deallocation of the buffers ✅ Reduced memory bandwidth consumption incurred when creating a new buffer which inevitably has to be filled with zeroes ✅ Timely deallocation of direct buffers https://netty.io/wiki/new-and-noteworthy-in-4.0.html
36. Netty uses native code
37. Platform specific libraries
38. Example: linux-aarch_64
39. Netty transports Core 🟢 JDK NIO Native transports 🟢 epoll 🟢 io_uring 🟢 kqueue
40. Netty optional libraries Native transports 📍 epoll transport 📍 io_uring transport 📍 kqueue transport Other 📍 tcnative boringssl 📍 brotli4j 📍 zstd-jni
41. Netty io_uring
42. io_uring support in Netflix Zuul ✅ https://github.com/Netflix/zuul/pull/1146
43. Socket options
44. DefaultSocketChannelConfig.java TCP_NODELAY
45. TCP_NODELAY https://brooker.co.za/blog/2024/05/09/nagle.html
46. TCP_NODELAY https://brooker.co.za/blog/2024/05/09/nagle.html The first thing I check when debugging latency issues in distributed systems is whether TCP_NODELAY is enabled
47. TCP_NODELAY https://brooker.co.za/blog/2024/05/09/nagle.html if you’re building a latency-sensitive distributed system running on modern datacenter-class hardware, enable TCP_NODELAY (disable Nagle’s algorithm) without worries
48. Netflix Zuul socket options https://github.com/Netflix/zuul/pull/1638
49. Netflix Zuul socket options https://github.com/Netflix/zuul/pull/1638
50. HTTP content compression
51. Netty compression support ✅ gzip ✅ snappy ✅ brotli ✅ zstd
52. HttpContentCompressor
53. zuul-integration-test
54. Netty pitfalls
55. Cookie class io.netty.handler.codec.http.Cookie io.netty.handler.codec.http.cookie.Cookie
56. HttpContentCompressor new HttpContentCompressor() new HttpContentCompressor((CompressorOptions[]) null)
57. Aborted (core dumped) Netty 4.1.98 + Epoll transport + Linux Netty and Java 21
58. https://netty.io/news/index.html Netty and Java 21
59. Netty resource leaks
60. https://netty.io/wiki/reference-counted-objects.html
61. https://netty.io/wiki/reference-counted-objects.html Since Netty version 4, the life cycle of certain objects are managed by their reference counts, so that Netty can return them (or their shared resources) to an object pool (or an object allocator) as soon as it is not used anymore.
62. “The disadvantage of reference counting is that it is easy to leak the reference-counted objects” source: Netty wiki
63. Resource leaks are difficult to debug
64. Netflix Zuul 2.x September 2017
65. Netty resource leak detector Leak Detector levels: - DISABLED - SIMPLE - ADVANCED - PARANOID
66. Best practices to avoid leaks “Run your unit tests and integration tests at PARANOID leak detection level” https://netty.io/wiki/reference-counted-objects.html
67. run Zuul integration test with PARANOID leak detection?
68. Netflix Zuul leak detection
69. Netflix Zuul leak detection assertZeroLeaks()
70. Netflix Zuul leak detection IntegrationTest.java
71. Netflix Zuul leak detection
72. implement a JUnit 5 Extension?
73. https://github.com/nettyplus/netty-leak-detector-junit-extension
75. JUnit 5 example pom.xml
76. JUnit 5 example
77. NettyLeakDetectorExtension
78. ✅ https://github.com/AsyncHttpClient/async-http-client/pull/1932
79. https://github.com/reactor/reactor-netty/pull/3064
80. Let’s talk about Apache Pinot
81. Pinot uses Netty
82. Pinot: QueryServer.java
83. Pinot leak detection ✅ https://github.com/apache/pinot/pull/12483
84. https://github.com/apache/pinot/pull/12577 Native transports
85. Let’s talk about security
86. CVE-2023-44487 “HTTP 2 Rapid Reset” October 2023
87. October 2023
88. HTTP/2 Rapid Reset “Ensure relevant web server and operating system patches are deployed across all Internet-facing Web Servers”
89. Netty and HTTP/2 Rapid Reset October 10, 2023
90. Spring Boot and Netty
91. Spring Boot web servers 🔷 JettyWebServer 🔷 NettyWebServer 🔷 UndertowWebServer 🔷 TomcatWebServer
92. Spring Boot with Netty
93. Spring Boot example https://github.com/sullis/spring-boot-netty-playground
94. what’s next for Netty?
95. Netty 🔵 Netty 4.2 🔵 Netty 5.0
96. Netty 4.2 branch
97. Netty 4.2 and io_uring
98. Final thoughts ✅ Netty is everywhere ✅ Netty is extensible ✅ Netty is awesome
99. Questions?
100. The End
101. Bonus content
102. Learning Netty
103. 📘 published December 2015 🤓 covers Netty 4.x
104. Stéphane Landelle @ Devoxx Belgium 2023
105. Dinesh Joshi @ Devoxx Ukraine 2018
106. Norman Maurer @ Devoxx Belgium 2016