Netty - Network - Application development the easy way

This presentation was hold as part of JAX 2013 in Mainz and cover Netty 4.

Transcript

1. Network - Application development the easy way @netty_project http://netty.io https://github.com/netty/netty
2. NORMAN MAURER Red Hat (JBoss) - EAP Core Team Former contractor for Apple Inc Author - Netty in Action Apache Software Foundation Member Netty / Vert.x Core-Developer and all things NIO Java and Scala Twitter: @normanmaurer Github: https://github.com/normanmaurer
3. WHAT IS NETTY ? “Netty is a NIO client server framework which enable quick and easy development of network applications such as protocol servers and clients...”
4. YET ANOTHER NETWORK FRAMEWORK ? YES!
5. “ @!# WTF, WHY SHOULD I CARE ? ”
6. FEATURES
7. FEATURES Asynchronous Simple and unified API High-Performing Listeners and Callbacks supported Zero-file-copy Buffer Pooling Gathering / Scattering ... and many more
8. ASYNCHRONOUS, WHAT DOES THIS MEAN ?
9. ASYNCHRONOUS... All I/O Operations don't block! Get notified once the operation completes Be able to share one Thread across many connections
10. “But synchronous / blocking IO served me well! Again, why should I care ?”
11. BLOCKING-IO MAY NOT SCALE! GOOD LUCK WITH SERVING 1 MILLION CONCURRENT CONNECTIONS “ Usually a Thread takes memory from 256kb to 1mb for the stack space! ”
12. NETTY TO THE RESCUE “Ouch....”
13. ASYNCHRONOUS IN ACTION C h a n n e l c h a n n e l = . . . C h a n n e l F u t u r e c f = c h a n n e l . w r i t e ( d a t a ) ; c f . a d d L i s t e n e r ( n e w C h a n n e l F u t u r e L i s t e n e r ( ) { @ O v e r r i d e p u b l i c v o i d o p e r a t i o n C o m p l e t e ( C h a n n e l F u t u r e f u t u r e ) t h r o w s E x c e p t i o n { i f ( ! f u t u r e . i s S u c c e s s ( ) { f u t u r e . c a u s e ( ) . p r i n t S t a c k t r a c e ( ) ; . . . } . . . } } ) ; . . . c f . s y n c ( ) ;
14. TRANSPORTS NIO OIO AIO Local Embedded “And more to come ....”
15. SUPPORTED PROTOCOLS TCP UDP SCTP* UDT Serial * O n l y s u p p o r t e d o n l i n u x
16. SIMPLE STATE MODEL
17. STATE FLOW
18. DATA CONTAINERS ByteBuf MessageBuf<T> “ByteBuffer on steroids!” “Queue like thing which can hold Message of type T”
19. BYTEBUF Separate index for reader/writer CompositeByteBuf Direct and Heap implementations Resizable with max capacity Support for reference-counting Method-Chaining B y t e B u f b u f = . . . ; b u f . w r i t e I n t ( 1 ) . w r i t e B y t e s ( d a t a ) . w r i t e B o o l e a n ( t r u e ) . . .
20. MESSAGEBUF Extend Queue Support reference-counting Type-safe!
21. CHANNELHANDLER “Time to process some data, heh ?”
22. CHANNELHANDLER “Your business logic needs a place, and this is where it belongs too”
23. CHANNELHANDLER FACTS Inbound vs. Outbound State vs. Operation Byte or Message based Always called by the assigned EventExecutor Type-safe
24. EXAMPLE USE CASES Convert data a.k.a Encoder / Decoder Business-Logic Handle state changes
25. PROVIDED CODECS “We have a lot of them!”
26. PROVIDED CODECS HTTP Websockets SPDY Serialization JBoss Marshalling Protobufs SSL Zlib
27. ADAPTERS ChannelInboundMessageHandlerAdapter ChannelInboundByteHandlerAdapter ChannelOutboundMessageHandlerAdapter ChannelOutboundByteHandlerAdapter “Makes your life easier”
28. ADAPTER IN ACTION @ S h a r a b l e p u b l i c c l a s s E c h o 4 S e r v e r H a n d l e r e x t e n d s C h a n n e l I n b o u n d B y t e H a n d l e r A d a p t e r { @ O v e r r i d e p u b l i c v o i d i n b o u n d B u f f e r U p d a t e d ( C h a n n e l H a n d l e r C o n t e x t c t x , B y t e B u f i n ) { B y t e B u f o u t = c t x . n e x t O u t b o u n d B y t e B u f f e r ( ) ; o u t . d i s c a r d R e a d B y t e s ( ) . w r i t e B y t e s ( i n ) ; c t x . f l u s h ( ) ; } @ O v e r r i d e p u b l i c v o i d e x c e p t i o n C a u g h t ( C h a n n e l H a n d l e r C o n t e x t c t x , T h r o w a b l e c a u s e ) { c t x . c l o s e ( ) ; } }
29. DECODER ByteToByteDecoder ByteToMessageDecoder MessageToMessageDecoder
30. ENCODER ByteToByteEncoder MessageToByteEncoder MessageToMessageEncoder
31. HYBRIDS ByteToByteCodec ByteToMessageCodec MessageToMessageCodec
32. OTHER OFTEN USEFUL DECODERS ReplayDecoder FixedLengthFrameDecoder LengthFieldBasedFrameDecoder LineBasedFrameDecoder DelimiterBasedFrameDecoder
33. WATCH OUT! Repeat with me: “I promise to never block the IO-Thread!”
34. You “Uhm well.... but my ChannelHandler needs to block. I'm screwed now ?”
35. “Hold on.... Netty is here for the rescue!”
36. CHANNELPIPELINE The home for all your ChannelHandlers
37. CHANNELPIPELINE Holds the ChannelHandlers for a Channel All events will get passed through it On the fly modification One-to-one relation between Channel and ChannelPipeline
38. CHANNELPIPELINE Kind of a unix-pipe-like thing... $ e c h o " N e t t y i s s h i t . . . . " | s e d - e ' s / i s / i s t h e / ' N e t t y i s t h e s h i t . . . . “You see, everything is adjustable!”
39. “But my ChannelHandler still block!” “ Ah yes, I forgot... ”
40. ADDING CHANNELHANDLERS C h a n n e l c h = . . . ; C h a n n e l P i p e l i n e p = c h . p i p e l i n e ( ) ; E v e n t E x e c u t o r e 1 = n e w D e f a u l t E v e n t E x e c u t o r ( 1 6 ) ; E v e n t E x e c u t o r e 2 = n e w D e f a u l t E v e n t E x e c u t o r ( 8 ) ; / / E x e c u t e d i n E v e n t L o o p T h r e a d p . a d d L a s t ( n e w M y P r o t o c o l C o d e c ( ) ) ; / / E x e c u t e d i n o n e o f t h e T h r e a d s o f e 1 p . a d d L a s t ( e 1 , n e w M y D a t a b a s e A c c e s s i n g H a n d l e r ( ) ) ; / / E x e c u t e d i n o n e o f t h e T h r e a d s o f e 1 p . a d d L a s t ( e 2 , n e w M y H a r d D i s k A c c e s s i n g H a n d l e r ( ) ) ;
41. EVENT-LOOP Someone needs to do the heavy work!
42. EVENT-LOOP One-to-Many relation between EventLoop and Channel Process "events" and hand over work to the ChannelPipeline
43. All the submitted Tasks will get executed in the IO-Thread! “ Yay, no need to worry about synchronization! ”
44. EVENTLOOP HIERARCHY “All the ScheduleExecutorService goodies for free!”
45. EVENTLOOP - HOW DOES IT WORK
46. RUN A TASK IN THE EVENTLOOP p u b l i c c l a s s M y H a n d l e r e x t e n d s C h a n n e l O u t b o u n d M e s s a g e H a n d l e r A d a p t e r { @ O v e r r i d e p u b l i c v o i d f l u s h ( C h a n n e l H a n d l e r C o n t e x t c t x , C h a n n e l P r o m i s e p r o m i s e ) { c t x . f l u s h ( p r o m i s e ) ; i f ( ! p r o m i s e . i s D o n e ( ) { / / s c h e d u l e t a s k f o r i n 3 0 s e c o n d s c t x . e x e c u t o r ( ) . s c h e d u l e ( n e w M y W r i t e T i m e o u t T a s k ( p r o m i s e ) , 3 0 , T i m e U n i t . S E C O N D S ) ; } / / R u n a n a r b i t r a r y t a s k f r o m a n I / O t h r e a d . c t x . e x e c u t o r ( ) . e x e c u t e ( n e w R u n n a b l e ( ) { . . . } ) ; } }
47. BOOTSTRAP YOUR APPLICATION “It's time to accept some real traffic”
48. BOOTSTRAP Fluent-API a.k.a DSL Graceful shutdown Lightweight
49. BOOTSTRAP A SERVER S e r v e r B o o t s t r a p b = n e w S e r v e r B o o t s t r a p ( ) ; t r y { b . g r o u p ( n e w N i o E v e n t L o o p G r o u p ( ) , n e w N i o E v e n t L o o p G r o u p ( ) ) . c h a n n e l ( N i o S e r v e r S o c k e t C h a n n e l . c l a s s ) . l o c a l A d d r e s s ( n e w I n e t S o c k e t A d d r e s s ( p o r t ) ) . c h i l d H a n d l e r ( n e w C h a n n e l I n i t i a l i z e r < S o c k e t C h a n n e l > ( ) { @ O v e r r i d e p u b l i c v o i d i n i t C h a n n e l ( S o c k e t C h a n n e l c h ) t h r o w s E x c e p t i o n { c h . p i p e l i n e ( ) . a d d L a s t ( n e w Y o u r C h a n n e l H a n d l e r ( ) ) ; } } ) ; C h a n n e l F u t u r e f = b . b i n d ( ) . s y n c ( ) ; f . c h a n n e l ( ) . c l o s e F u t u r e ( ) . s y n c ( ) ; } f i n a l l y { b . s h u t d o w n ( ) ; }
50. BOOTSTRAP A CLIENT B o o t s t r a p b = n e w B o o t s t r a p ( ) ; t r y { b . g r o u p ( n e w N i o E v e n t L o o p G r o u p ( ) ) . c h a n n e l ( N i o S o c k e t C h a n n e l . c l a s s ) . r e m o t e A d d r e s s ( n e w I n e t S o c k e t A d d r e s s ( " 1 0 . 0 . 0 . 1 " , 2 5 ) ) . h a n d l e r ( n e w C h a n n e l I n i t i a l i z e r < S o c k e t C h a n n e l > ( ) { @ O v e r r i d e p u b l i c v o i d i n i t C h a n n e l ( S o c k e t C h a n n e l c h ) { c h . p i p e l i n e ( ) . a d d L a s t ( n e w Y o u r C h a n n e l H a n d l e r ( ) ) ; } } ) ; C h a n n e l F u t u r e f = b . c o n n e c t ( ) . s y n c ( ) ; f . c h a n n e l ( ) . c l o s e F u t u r e ( ) . s y n c ( ) ; } f i n a l l y { b . s h u t d o w n ( ) ; }
51. GENERAL ASL2 license Hosted at Github Community-driven
52. COMPANIES Red Hat Twitter Facebook Boundary Typesafe “And many more... ”
53. OPENSOURCE PROJECTS HornetQ Infinispan Vert.x Play Framework Finangle Cassandra “And again many more....”
54. THINGS TO COME Chained ChannelPipelines Native edge-triggered Transport* Lambda support
55. OTHER NIO FRAMEWORKS Apache MINA Grizzly HawtDispatch* JBoss XNIO*
56. GET INVOLVED Mailinglist https://groups.google.com/forum/#!forum/netty IRC #netty irc.freenode.org Website http://netty.io GitHub https://github.com/netty/netty/
57. TOO LOW LEVEL ? “You may like Vert.x which is based on Netty and also polyglot!”
58. NOT ENOUGH INFO? http://www.manning.com/maurer/ “You may want to buy my book...”
59. “Questions please!”
60. THANKS!