Presentation given at the International PHP Conference 2012 in Mainz, about the REST architectural style.

1. Alessandro Nadalin | NAMSHI.com
REST in peace

2. AGENDA
●Vol. 1: REST in a nutshell
○Tenets
○Antipatterns
●Vol. 2: To the rescue
○HTTP cache
○HATEOAS

3. Sorry for the ugly slide.
There will be others.
Really sorry.

4. REST in a nutshell:
1. Client <> Server

5. REST in a nutshell:
2. Stateless

6. REST in a nutshell:
3. Cacheable

7. REST in a nutshell:
4. Layered system

8. REST in a nutshell:
5. Uniform
interface

9. And obviously nobody had a clue

10. ANTIPATTERNS

11. 1
URIs

12. "REST is about
cool URI design"
http://apple.com/users/1/licenses/4.json

13. "REST is about
cool URI design"
http://apple.com/users/1/licenses/4.json

14. http://apple.com/site/en_US/showUsers.jsp?
uid=1&license=4
is OK too

15. but

16. cool URIs help you
think in term of resources
David Zuelke

17. 2
URIs (bis)

18. REST follows a URI schema
GET /users
POST /users
PUT /users/{id}
DELETE /users/{id}
...

19. REST follows a URI schema
GET /users
POST /users
PUT /users/{id}
DELETE /users/{id}
...

20. what if you change your
URL?

21. Yeah,
client is
broken

22. RESTful clients should
be driven by service's
hypermedia controls
Roy Fielding : http://roy.gbiv.com/untangled/2008/rest-apis-must-be-
hypertext-driven

23. HATEOAS

24. 3
POST is cool

25. said SOAP 1.1

26. said SOAP 1.1

27. loosing meaningful verbs at the protocol
level

28. loosing meaningful verbs at the protocol
level
nothing cacheable by default

29. loosing meaningful verbs at the protocol
level
nothing cacheable by default
what about bookmarking?

30. 4
500 is your friend

31. said SOAP
( again )

32. GET /users/300
Host: www.example.
com

33. GET /users/300
Host: www.example.
com
HTTP/1.1 500 Internal Server
Error
Etag: 1234
X-Powered-By: php/5.3
...
The record cannot be found

34. GET /users/300
Host: www.example.
com
HTTP/1.1 500 Internal Server
Error
Etag: 1234
X-Powered-By: php/5.3
...
The record cannot be found

35. The HTTP protocol is awesome,
and lets you return meaningful and
universally-understood status codes

36. 404 Not Found

37. 202 Accepted

38. 202 Accepted
You get an immediate OK, and the operation will hopefully complete

39. Pause

40. World Wide
Web

41. the largest data-exchange network on the planet

42. And meanwhile, at Facebook...
12TB of new data every
day
(2 years ago)
500 million users

43. And meanwhile, at Google...
1 billion
unique monthly googlers

44. via HTTP , baby!

45. HTTP in a nutshell:
1. Client <> Server

46. HTTP in a nutshell:
2. Stateless

47. HTTP in a nutshell:
3. widespread cache spec
http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html

48. HTTP in a nutshell:
Firefox
Company proxy
Great chinese (fire)wall
Reverse proxy
Origin server
4. Layered system

49. HTTP in a nutshell:
5. it is the uniform interface
between clients and servers

50. HTTP bleeds
REST

51. 1.
caching & scalability

52. Types of cache
Local
Shared/proxy
Shared/reverse proxy

53. Types of cache
Local
Shared/proxy
Shared/reverse proxy

55. Types of cache
Local
Shared/proxy
Shared/reverse proxy

57. Types of cache
Local
Shared/proxy
Shared/reverse proxy

59. on the server side

60. Caching with
Expiration
(example)

61. HTTP/1.1 200 OK
Host: www.example.com
Expires: 0

62. HTTP/1.1 200 OK
Host: www.example.com
Expires: 0

63. HTTP/1.1 200 OK
Host: www.example.com
Expires: Tue, 31 Jan 2013 01:00 GMT

64. HTTP/1.1 200 OK
Host: www.example.com
Cache-Control: max-age=60, public

65. HTTP/1.1 200 OK
Host: www.example.com
Cache-Control: max-age=60, public

66. HTTP/1.1 200 OK
Host: www.example.com
Cache-Control: max-age=60, public
Cacheable for 60 seconds

67. HTTP/1.1 200 OK
Host: www.example.com
Cache-Control: max-age=60, public
Cacheable by both local and shared caches

68. but hey, you say

69. HTTP's cache fails when dealing with really dynamic
pages, because consumers will always have to hit the
origin server, although a part of the page would be
cacheable ( header and footer, for example )

70. Nope
Nope

71. ESI was built for that
http://www.w3.org/TR/esi-lang

72. <esi:include src="http://php2start.com/talks/1" />

73. <esi:include src="http://php2start.com/talks/1" />

74. <esi:include src="http://php2start.com/talks/1" />

75. 1s (tweets)
3600 post

76. <esi:include src='tweets.html' />
<esi:include src='article/12.html' />

77. So what does HTTP cache is meant to solve?

78. Less work

79. http://www.flickr.
com/photos/snakphotography/5004775320/sizes/o/in/photostream/
because the hard work is delegated to the browser/proxy

80. evolve

81. because cache is abstracted from the
application

82. loose coupling

83. because caching is bound to the protocol, HTTP, not
to your implementation ( Sf, RoR, Django )

84. 2.
adaptability & durability

85. Hypermedia
another long-time friend

86. Links
outrageously simplifying

87. <link rel="payment" href="/checkout" type="text/html" ... />

88. <link rel="payment" href="/checkout" type="text/html" ... />

89. <link rel="payment" href="/checkout" type="text/html" ... />

90. <link rel="payment" href="/checkout" type="text/html" ... />

91. POST /users
Host: www.example.
com
HTTP/1.1 201 Created
Host: www.example.com
Etag: 1234
X-Powered-By: php/5.3
Location: /users/1

92. POST /users
Host: www.example.
com
HTTP/1.1 201 Created
Host: www.example.com
Etag: 1234
X-Powered-By: php/5.3
Location: /users/1

93. POST /users
Host: www.example.
com
HTTP/1.1 201 Created
Host: www.example.com
Etag: 1234
X-Powered-By: php/5.3
Location: /new-users-db/1

94. POST /users
Host: www.example.
com
HTTP/1.1 201 Created
Host: www.example.com
Etag: 1234
X-Powered-By: php/5.3
Location: /new-users-db/1

95. consumers of your API are able to follow
the changes of your design

96. everything seems
cool
But why REST?

97. Pros
Performances

98. Pros
Scalability

100. Pros
Durability

101. amazon.com

102. Alex Nadalin

103. Alex Nadalin
odino.org

104. Alex Nadalin
odino.org
@_odino_

105. Alex Nadalin
odino.org
@_odino_

106. Alex Nadalin
odino.org
@_odino_

107. Alex Nadalin
odino.org DXB
@_odino_

108. Alex Nadalin
odino.org DXB
@_odino_

109. We're hiring!

110. In Dubai.

111. In Dubai.
alex.nadalin@namshi.com

112. In Dubai.
alex.nadalin@namshi.com
@_odino_

113. In Dubai.
alex.nadalin@namshi.com
@_odino_
TALK TO ME!

114. Credits
http://www.flickr.com/photos/larachris/16564077/sizes/o/in/photostream/
http://www.flickr.com/photos/ashatenbroeke/4367373081/sizes/z/in/photostream/
http://www.flickr.com/photos/yourdon/3140270189/sizes/l/in/photostream/
http://www.flickr.com/photos/jox1989/4964706072/sizes/l/in/photostream/
http://www.flickr.com/photos/brainfg/168506259/sizes/o/in/photostream/
http://www.flickr.com/photos/norte_it/3897091546/sizes/o/in/photostream/
http://www.zdnet.com/blog/service-oriented/soap-versus-rest-a-matter-of-style/3568
http://www.flickr.com/photos/turtlemom_nancy/2046347762/sizes/l/in/photostream/
http://www.flickr.com/photos/juanpg/3333385784/sizes/z/in/photostream/
http://www.flickr.com/photos/congvo/301678287/sizes/l/in/photostream/
http://www.flickr.com/photos/ihasb33r/2573196546/sizes/z/in/photostream/
http://www.flickr.com/photos/martin_heigan/4544138976/sizes/o/in/photostream/
http://www.flickr.com/photos/cknara/4195099999/sizes/o/in/photostream/
http://www.flickr.com/photos/1080p/3076529265/sizes/l/in/photostream/
http://www.flickr.com/photos/adamrice/280300202/sizes/l/in/photostream/
http://www.flickr.com/photos/tomer_a/541411897/sizes/o/in/photostream/
http://www.flickr.com/photos/subpra/4514008262/sizes/l/in/photostream/
http://www.flickr.com/photos/lippincott/2539720043/sizes/l/in/photostream/
http://www.flickr.com/photos/rawryder/5086090931/sizes/l/in/photostream/
http://www.flickr.com/photos/robboudon/5312731161/sizes/l/in/photostream/
http://www.flickr.com/photos/bc-burnslibrary/4158243488/sizes/o/in/photostream/
http://www.flickr.com/photos/13606325@N08/2416993706/sizes/o/in/photostream/
http://www.flickr.com/photos/neothezion/5135841069/sizes/l/in/photostream/
http://www.flickr.com/photos/planetschwa/2494067809/
http://www.flickr.com/photos/thomasthomas/258931782/
http://www.flickr.com/photos/rustyboxcars/2629631562/sizes/l/in/photostream/
http://www.flickr.com/photos/ell-r-brown/4138727474/sizes/l/in/photostream/
http://www.flickr.com/photos/noah123/5082076630/sizes/z/in/photostream/
http://www.flickr.com/photos/jungle_boy/220181177/sizes/l/in/photostream/
http://www.flickr.com/photos/prettydaisies/872539081/sizes/l/in/photostream/
http://www.flickr.com/photos/kaptainkobold/76256150/sizes/o/in/photostream/
http://www.flickr.com/photos/uomoincravatta/1438372865/sizes/z/in/photostream/