How we at Etsy are adding concurrent data access to our PHP API. From PHP Day 2014

1. Concurrent PHP
in the Etsy API
Matthew Graham
@lapsu
@EtsyAPI Lead
#phpday
2014 April

2. @lapsu@EtsyAPI

3. @lapsu@EtsyAPI
$1.3 Billion
Things That Matter

4. @lapsu@EtsyAPI

5. @lapsu
Etsy's PHP
www api admin
queues cron
@EtsyAPI

6. @lapsu
~200 engineers
30+ deploys / day
@EtsyAPI

7. Also, Rasmus
@lapsu@EtsyAPI

8. Spoilers
@lapsu
Mobile Clients Are Special
1 Thread != No Concurrency
@EtsyAPI

9. @lapsu
<motivation>
@EtsyAPI

10. Premise:
@lapsu
The Future is Mobile
@EtsyAPI

11. @lapsu
Past
The Future is Mobile
November 2013
@EtsyAPI

12. @lapsu@EtsyAPI

13. @EtsyAPI
Mobile Networks Suck
@lapsu
<

14. @EtsyAPI
Not Mobile
@lapsu
www.etsy.com/shop/AVintageWanderer

15. @EtsyAPI
Network Performance
@lapsu
3G < 4G

16. @EtsyAPI
Network Coverage
@lapsu
3G > 4G

17. @EtsyAPI
Mobile Requests
@lapsu
More != Better

18. @lapsu@EtsyAPI

19. @lapsu
1000ms Time To Glass
@EtsyAPI

20. @lapsu
1000ms
- 900ms
-------------
100ms
Network/Client
------------------------
Server
@EtsyAPI

21. @lapsu
100ms = Bespoke
+ Concurrent
@EtsyAPI

22. @lapsu
Single Threads
@EtsyAPI

23. Concurrency
@lapsu@EtsyAPI
Main “Thread”
Child “Thread” Child “Thread”

24. @lapsu
</motivation><interface>
@EtsyAPI

25. Paul goes to Netflix
@lapsu@EtsyAPI

26. 1 View : 1 Bespoke
@lapsu@EtsyAPI
ClientView
Bespoke
View View
Bespoke Bespoke
API

27. Multiple Clients
@lapsu@EtsyAPI
ClientsView
Bespoke
View View
Bespoke Bespoke
API

28. Bespoke : Components
@lapsu@EtsyAPI
Bespoke Bespoke Bespoke
API
Item User Shop Favs Tx

29. Components as REST
@lapsu@EtsyAPI
Bespoke Bespoke
API
Item User Shop Favs Tx

30. @lapsu
?includes=User
@EtsyAPI

31. Android User View
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

32. Concurrent Client
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

33. Making Requests
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

34. @lapsu@EtsyAPI
shop
favs
t0 t1

35. Inputs
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

36. Future Parameters
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

37. @lapsu@EtsyAPI
shop
favs
items
t0 t1 t2 t3 t4

38. ~6 Lines
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

39. @lapsu
</interface><performance>
@EtsyAPI

40. @lapsu
Web Pages Are Clients Too
@EtsyAPI

41. Web First
@lapsu@EtsyAPI

42. API First
@lapsu@EtsyAPI

43. Android User View
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
Curl_Orchestrator::run(
[$shop,$favs,$items]);
return [$favs,$items];
}
@EtsyAPI

44. Desktop Web User View
@lapsu
function handle($cli, $inp) {
$shop = $cli->shop($inp->user_id);
$favs = $cli->favs($inp->user_id);
$items = $cli->items($shop->shop_id);
$teams = $cli->teams($inp->user_id);
Curl_Orchestrator::run(
[$shop,$favs,$items,$teams]);
return [$favs,$items,$teams];
}
@EtsyAPI

45. @lapsu
Activity Feed
@EtsyAPI

46. @lapsu
Activity Feed
Page
@EtsyAPI
Home
Page

47. 30s of HTTP Time
@lapsu@EtsyAPI

48. 30s of HTTP Time
@lapsu
880ms Real Time
@EtsyAPI

49. Components
@lapsu@EtsyAPI
Bespoke Bespoke Bespoke
API
Item User Shop Favs Tx

50. Components Cache
@lapsu@EtsyAPI
Bespoke Bespoke Bespoke
Cache
API
Item User Shop Favs Tx

51. Local Call
@lapsu@EtsyAPI
Me

52. Long Distance Call
@lapsu@EtsyAPI
Atlantic
Ocean User

53. Long Distance Call
@lapsu@EtsyAPI
Atlantic
Ocean
API
Templates
User

54. @lapsu
</performance><internals>
@EtsyAPI

55. @lapsu
curl_multi_*
@EtsyAPI

56. @lapsu@EtsyAPI
curl?

57. General Sequence
@lapsu@EtsyAPI
curl_multi_init();
curl_multi_add();
curl_multi_exec();
while (!$done) {
curl_multi_select();
curl_multi_exec();
curl_multi_info_read();
}

58. curl_multi_init
@lapsu@EtsyAPI
$mh = curl_multi_init();

59. curl_multi_add_handle
@lapsu@EtsyAPI
$mh = curl_multi_init();
$ch = curl_init($url);
curl_setopt_array($ch, $options);
curl_multi_add_handle($mh, $ch);

60. @lapsu@EtsyAPI
multi handle
handle handle handle

61. curl_multi_exec
@lapsu@EtsyAPI
do {
$code = curl_multi_exec($mh, $r);
} while ($code == CURLM_CALL_MULTI_PERFORM);

62. curl_multi_select
@lapsu@EtsyAPI
$cnt = curl_multi_select($mh, $tmout);

63. curl_multi_info_read
@lapsu@EtsyAPI
$info = curl_multi_info_read($mh);
$ch = $info['handle'];
$content = curl_multi_getcontent($ch);

64. @lapsu@EtsyAPI

65. localhost: Expected
@lapsu@EtsyAPI
R1
R2
R3
t0

66. Network: Actual
@lapsu@EtsyAPI
R2
R3
t0 t1
R1

67. curl Protocols
@lapsu@EtsyAPI
HTTP
LDAP
Gopher POP3
IMAP
TELNET TFTP

68. curl_get_multi_handle_state
@lapsu@EtsyAPI
$state = CURLM_STATE_FIRST;
curl_multi_get_handle_state(
$mh, $ch, $state);
$sent = $state > CURLM_STATE_FIRST
&& $state < CURLM_STATE_PERFORM;

69. Expected, Actual
@lapsu@EtsyAPI
R1
R2
R3
t0

70. Revised Sequence
@lapsu@EtsyAPI
curl_multi_init();
curl_multi_add();
while (!$sent) {
curl_multi_exec();
curl_multi_get_handle_state();
}
while (!$done) {
curl_multi_select();
curl_multi_exec();
curl_multi_info_read();
}

71. Still Headed Upstream
@lapsu@EtsyAPI

72. Patch URL
@lapsu
bit.ly/etsy_curl_multi_patch
@EtsyAPI

73. Recursion?
@lapsu@EtsyAPI

74. Recursion?
@lapsu
No.
@EtsyAPI

75. Recursion?
@lapsu
No?
Not yet.
@EtsyAPI

76. Visibility
@lapsu@EtsyAPI

77. @lapsu
PHP Coroutines
@EtsyAPI

78. More Code
@lapsu
Available Upon Request
@EtsyAPI

79. @lapsu
codeascraft.etsy.com
@EtsyAPI

80. @lapsu
</internals><wrap/>
@EtsyAPI

81. @lapsu
Address Mobile Challenges
@EtsyAPI

82. @lapsu
PHP Does Concurrency
@EtsyAPI

83. PHP Abides
@lapsu@EtsyAPI

84. Concurrent PHP
in the Etsy API
Matthew Graham
@lapsu
@EtsyAPI Lead
#phpday
2014 April
Thank You

85. Reminder:
@lapsu
Repeat the questions
@EtsyAPI

86. @lapsu
SPDY / HTTP 2.0
@EtsyAPI