Vert.x: This ain't your Dad's Node! (As presented at http://sfjava.org on 10/9/2012)

1. Vert.x:
This ain’t your Dad’s Node!
Matt Stine
Tim Fox
Enterprise Java/Cloud Consultant
Father of Vert.x
matt.stine@gmail.com
http://mattstine.com
Twitter: @mstine

2. The
C10K
Problem

4. SERVER
PUSH

5. Ryan Dahl
Father of Node.js
How?!?!

6. 2008:
Thread Per Request/Response

7. http://www.xtranormal.com/watch/6995033/mongo-db-is-web-scale

8. Non-blocking UNIX sockets

12. But Node
has some
shortcomings...
1. JavaScript!
2. Vertical Scaling
3. Interprocess
Communication
4. Event Loop

13. http://vertx.io

14. Problem #1:
JavaScript
Brendan Eich
Father of JavaScript

15. WAT
https://www.destroyallsoftware.com/talks/wat

16. Solution #1:
Polyglot
Programming
Neal Ford
Father of Polyglot Programming
http://memeagora.blogspot.com/2006/12/polyglot-programming.html

17. Hello World
in every Vert.x language!

18. Java

20. Ruby

21. Python

22. JavaScript

24. FUTURE
Theoretically, any JVM language or language that compiles
to a supported language (e.g. ClojureScript ➔ JavaScript)

25. Problem #2:
Vertical
Scaling
Lars Bak
Father of V8

26. http://nodejs.org/about/

27. Node: Up and Running
Example 3-11: Using cluster to distribute work

28. Solution #2:
The
JVM
James Gosling
Father of Java

29. The Verticle
- Unit of Deployment
Verticle
- Script/Java Class

30. Vert.x Instance
How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop
Event Loops
App registers App registers App registers App registers trigger Events trigger Events trigger Events trigg
Events
handlers handlers handlers handlershandlers handlers handlers handlers
• Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
– on a single threada single threada single threada single thread
– on – on – on
• Use handlersUse handlersUse handlersUse handlers to pass messages
• to pass messages messages messages
• to pass • to pass
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
– EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages
– Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
Verticle 9 9 9
Runtime.availableProcessors() == 4

31. Vert.x Instance
How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop
Event Loops
App registers App registers App registers App registers trigger Events trigger Events trigger Events trigg
Events
handlers handlers handlers handlershandlers handlers handlers handlers
• Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
– on a single threada single threada single threada single thread
– on – on – on
• Use handlersUse handlersUse handlersUse handlers to pass messages
• to pass messages messages messages
• to pass • to pass
vertx run • Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
HelloWorld with EventBus with EventBus with EventBus with messages
– EventBus – messages – messages – messages
– Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
-instances 4 Verticle Verticle Verticle Verticle 9 9 9
Runtime.availableProcessors() == 4

32. Concurrency
• Verticle instance assigned thread/event loop.
• Verticle instance ALWAYS executes on
assigned thread.
• Verticles have isolated classloaders and
cannot share global state (static members,
global variables, etc.)
• Can write all code assuming single
threading.

33. Tony Hoare
Father of CSP
(http://dl.acm.org/citation.cfm?
doid=359576.359585)
Problem #3:
Interprocess
Communication

34. Node.js Communication Options
• TCP/UDP/UNIX Sockets
• Redis Pub/Sub (http://redis.io/)
• ZeroMQ (http://www.zeromq.org/)
• Process Signaling/Cluster Module
• Eventing Frameworks: Hook.io (dead), JS-
Signals, Bean, etc.
• Memcached
• Etc...

35. Solution #3.1:
The
Event
Bus
Alan Kay
Father of Smalltalk

36. How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop
App registers App registers App registers App registers trigger Events trigger Events trigger Events trigger
Events
handlers handlers handlers handlershandlers handlers handlers handlers
• Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
– on a single threada single threada single threada single thread
– on – on – on
• Use handlersUse handlersUse handlersUse handlers to pass messages
• to pass messages messages messages
• to pass • to pass
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
– EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages
– Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
Verticle Verticle Verticle Verticle 9 9 9 9
Event Bus

37. Addressing
• Simply a String
• Dot-style namespacing recommended
• e.g. “messages.inbound.A”

38. Handler Registration
Handler X
messages.inbound.A Handler Y
Handler Z

39. Handler Registration

40. Pub/Sub
Handler X
Sender messages.inbound.A Handler Y
Handler Z

41. Pub/Sub

42. P2P
Handler X
Sender messages.inbound.A Handler Y
Handler Z

43. P2P

44. Sender:
Receiver:

45. Message Types
• String
• Primitives (int, long, short, float, double, ...)
• Boxed Primitives
• boolean/Boolean
• org.vertx.java.core.json.JsonObject
• org.vertx.java.core.buffer.Buffer

46. Distributed Vert.x
orks it works it works it works
How How How How it works it works it works it works
How How How How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop
rs App registers App registers App registers trigger Events trigger Events trigger Events trigger registers App registers trigger Events trigger Events trigger Events trigger registers App registers trigger Events trigger Events trigger
Events App registers App registers App Events App registers App registers App Events
handlers handlers handlershandlers handlers handlers
handlers handlers
handlers handlers handlershandlers handlers handlers
handlers handlers
handlers handlers handlershandlers handlers handlers
executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers • Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers • Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
le threada single threada single threada single thread
– on – on – on – on a single threada single threada single threada single thread
– on – on – on – on a single threada single threada single threada single thread
– on – on – on
ersUsepass messages messages messages messages handlersUsepass messages messages messages messages handlersUse handlersUsepass messages messages messages
• to handlersUse handlersUsepass
• to pass • to handlers to pass • Use • to handlersUse handlersUsepass
• to pass • to handlers to pass • Use • to pass messages
• to handlersUse handlers to pass
• to pass
application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms Inter/intra application comms
• • Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
s with EventBus with EventBus with EventBus with messages
– messages – messages – messages – EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages – EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages
red data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared – Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared – Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
Verticle Verticle Verticle 9
Verticle9 9
Verticle
9
Verticle Verticle 9
Verticle
9 9
Verticle
9
Verticle Verticle 9
Verticle
9 9
Event Bus

47. Into the Browser!
orks it works it works it works
How How How How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop Event loop Event loop Event loop Event loop
rs App registers App registers App registers trigger Events trigger Events trigger Events trigger registers App registers trigger Events trigger Events trigger Events trigger
Events App registers App registers App Events
handlers handlers handlershandlers handlers handlers
handlers handlers
handlers handlers handlershandlers handlers handlers handlers
executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers • Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
le threada single threada single threada single thread
– on – on – on – on a single threada single threada single threada single thread
– on – on – on
ersUsepass messages messages messages messages handlersUsepass messages messages messages messages
• to handlersUse handlersUsepass
• to pass • to handlers to pass • Use • to handlersUse handlersUsepass
• to pass • to handlers to pass
application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
s with EventBus with EventBus with EventBus with messages
– messages – messages – messages – EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages
red data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared – Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
Verticle Verticle Verticle 9
Verticle9 9
Verticle
9
Verticle Verticle 9
Verticle
9 9 9
SockJS Bridge
Event Bus

48. The Server

49. The Client

50. Demo

51. Solution #3.2:
Shared
Immutable
State
Rich Hickey
Father of Clojure

52. e.g. In-memory Web
Cache

53. MessageAI L
Passing?
F

54. Shared state only
dangerous if it is
MUTABLE!

55. Vert.x Shared State
• SharedData Object (vertx.sharedData())
• collection of
java.util.concurrent.ConcurrentMap<K,V>
• collection of java.util.Set<E> (backed by
ConcurrentMap)
• Elements MUST be immutable values (well,
sort of...)
• Currently only available within a Vertx.
instance, not across a cluster.

56. Allowed Values
• Strings
• Boxed Primitives
•byte[]
R !
•org.vertx.java.core.buffer.Buffer
• Implementors of
G E
Shareable
AN
org.vertx.java.core.shareddata.
D

57. Shared Map

58. Shared Set

59. Problem #4:
The
Event
Loop
Douglas Schmidt
Father of the Reactor Pattern

60. Reactor
w it works Pattern Review
Event loop
Application ...events
pp registers
registers Events t
trigger
handlers handl
handlers... handlers.
Event Loop
andlers executed synchronously
on a single thread
se handlers to pass messages

61. Reactor Pattern Review
• Single thread / single event loop
• EVERYTHING runs on it
• You MUST NOT block the event loop

62. Reactor Pattern Problems
• Some work is naturally blocking:
• Intensive data crunching
• 3rd-party blocking API’s (e.g. JDBC)
• Pure reactor (e.g. Node.js) is not a good fit
for this kind of work!

63. Solution #4:
Worker
Verticles
Carl Hewitt
Father of the Actor Model

64. Worker Verticles
• Not assigned a Vert.x event loop thread
• Executes on background thread pool
• Never executed concurrently by more than
one thread
• Not allowed to use TCP or HTTP clients/
servers
• Communicate using the event bus
• Should be kept to a minimum

65. The “Multi-reactor”
How it works it works it works it works
How How How
Event loop Event loop Event loop Event loop
BG BG
App registers App registers App registers App registers trigger Events trigger Events trigger Events trigger
Events
handlers handlers handlers handlershandlers handlers
Pool
handlers
Pool
handlers
• Handlers executed synchronously executed synchronously
• Handlers executed synchronously executed synchronously
• Handlers • Handlers
– on a single threada single threada single threada single thread
– on – on – on
• Use handlersUse handlersUse handlersUse handlers to pass messages
• to pass messages messages messages
• to pass • to pass
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
• Inter/intra application comms
– EventBus with EventBus with EventBus with EventBus with messages
– messages – messages – messages
– Safe shared data structuresdata structuresdata structuresdata structures
– Safe shared – Safe shared – Safe shared
Worker Worker
Verticle Verticle Verticle Verticle
Verticle Verticle
9 9 9 9
Event Bus

68. Problem/Solution Summary
• Node.js compels the use of JavaScript
• Vert.x is Polyglot
• Node.js is inherently single-threaded
• Vert.x leverages the multi-threaded JVM

69. Problem/Solution Summary
• Node.js doesn’t help much w/ interprocess
communication
• Vert.x features a distributed event bus which
reaches all the way into the browser
• Node.js requires all code to run on the event
loop
• Vert.x features background workers that
allow blocking work to be done off of the
event loops

70. Other Goodies
• Growing Module • TCP/SSL servers/clients
Repository • HTTP/HTTPS servers/
clients
• web server
• persistors (Mongo, • WebSockets support
JDBC, ...) • SockJS support
• work queue • Timers
• authentication • Buffers
manager
• Streams and Pumps
• session manager • Routing
• Socket.IO • Asynchronous File I/O

71. Case Study
https://github.com/mstine/twitx

72. Get Involved!
• Google Group: http://groups.google.com/
group/vertx
• GitHub: https://github.com/vert-x/vert.x
• IRC: irc://freenode.net/vertx
• Needs:
• language implementations
• modules (esp. persistence, security, ...)
• examples/blogs/documentation help

73. Vert.x:
This ain’t your Dad’s Node!
Matt Stine
Enterprise Java/Cloud Consultant
Please fill out an evaluation:
matt.stine@gmail.com
http://mattstine.com
http://speakerrate.com/talks/16821
Twitter: @mstine

74. Image Credits
• Tim Fox: https://twitter.com/timfox
• BSOD Phone: http://www.flickr.com/photos/markhillary/3413357033
• V8: http://www.flickr.com/photos/gorbould/3479298062
• Ryan Dahl: http://www.flickr.com/photos/franksvalli/5163205409
• Shortcomings: http://www.flickr.com/photos/hendricksphotos/3340896056
• Brendan Eich: http://www.flickr.com/photos/equanimity/4055148344
• Neal Ford: http://nealford.com/images/Neal-2012-headshot.jpg
• Lars Bak: http://www.flickr.com/photos/niallkennedy/2822229099
• James Gosling: http://www.flickr.com/photos/skrb/2499736195
• Tony Hoare: http://www.flickr.com/photos/adewale_oshineye/3687557065
• Alan Kay: http://www.flickr.com/photos/mwichary/3010026816
• Rich Hickey: http://www.flickr.com/photos/hlship/3603090614
• Douglas Schmidt: http://www.cs.wustl.edu/~schmidt/gifs/SchmidtD.jpg
• Carl Hewitt: http://www.flickr.com/photos/jeanbaptisteparis/3098594954