As presented at Confoo 2013. More than some arcane NoSQL tool, Redis is a simple but powerful swiss army knife you can begin using today. This talk introduces the audience to Redis and focuses on using it to cleanly solve common problems. Along the way, we'll see how Redis can be used as an alternative to several common PHP tools.

1. Redis For The
Everyday Developer
Ross Tuck
Confoo
March 1st, 2013

2. Who Am I?

3. Ross Tuck

4. Team Lead at Ibuildings
Codemonkey
HTTP nut
Hat guy

5. @rosstuck

6. Boring.

8. NoSQL

9. NoNoSQL

10. Evaluation

11. • Created by Salvatore Sanfilippo ( @antirez )
• Sponsored by VMware
• 4 years old
• redis.io

12. “Redis is an open source, advanced
key-value store.”

13. “It is often referred to as
a data structure server...”

14. Defancypants

15. Redis
Server A Server B

16. In-Memory

17. In-Memory

18. The Cool Stuff

19. Fast.

20. Demo.

21. Oh wait, it's already done.

22. 120,000~ ops per sec

23. Flexible.

24. (optionally)
Persistent.

25. Replication
Pub/Sub
Transactions
Scripting
Slices
Dices
Makes julienne fries

26. “Well, Ross, that sounds cool...”

28. +
MySQL Redis

29. MySQL
+
Redis
4ever

30. Setup

31. apt-get install redis-server
Easy but old

32. http://redis.io/download

33. PHP Libraries
• 5.3+: Predis
• 5.2: Predis or Rediska
• C Extension: phpredis
• redis-cli

34. $client = new PredisClient();

35. The Surprise Ending

36. PHP
MySQL
Memcache

37. PHP
MySQL
Memcache

38. PHP
MySQL
Redis

39. It's about 80% cases.

40. Use Case #1: Caching

41. Redis has commands.

42. Commands have parameters.

43. Think functions.

44. $client->commandGoesHere($params, $go, $here);

45. SET

46. $client->set('ross:mood', 'nervous');
// Later
$client->get('ross:mood'); // returns “nervous”

47. $client->set('ross:mood', 'nervous');
$client->expire('ross:mood', 5);
// 4 seconds later...
$client->get('ross:mood'); // “nervous”
// 5 seconds later...
$client->get('ross:mood'); // null

48. $client->set('ross:mood', 'nervous');
$client->expire('ross:mood', 5);

49. $client->setex('ross:mood', 5, 'nervous');

50. Great for caching

51. Ideal for sessions

52. Use Case #2: Simple Data

53. Search...
omg cheezburgers in the lunchroom
today. Better hurry if u want 1!!! ^_^
How do I store this?

54. key value

55. key value
homepage_message omg cheezburgers...

56. key value
homepage_message omg cheezburgers...
tps_reports new cover pages on...

57. You already know it.

58. $client->set('home:message', 'cheezburgers...');
$client->get('home:message');

59. Equal
Easier
More Fun

60. Use Case #3: Hit Counters

62. increment

63. $client->incr('page:42:views'); // 1
$client->incr('page:42:views'); // 2
$client->incr('page:42:views'); // 3

64. Redis is hard ;)

65. How is this better?

67. Fast?

68. redis-benchmark
====== INCR ======
10000 requests completed in 0.08 seconds
50 parallel clients
3 bytes payload
keep alive: 1
100.00% <= 0 milliseconds
119047.62 requests per second

69. Fast enough.

70. $client->incr('cookies:eaten');
$client->incrBy('cookies:eaten', 2);
$client->incrByFloat('cookies:eaten', 0.5); version 2.6+

71. Use Case #4: Latest News

73. “It is often referred to as
a data structure server...”

74. “...since keys can contain strings, hashes,
lists, sets and sorted sets.”

75. $redis = array();

76. Generic
Hash
List
Set
Sorted Set

77. Generic
Hash // strings and numbers
List $redis['ross:mood'] = "happy";
Set $redis['foo'] = 9;
Sorted Set

78. Generic
Hash // associative array
List $redis['foo']['name'] = 'Bob';
$redis['foo']['age'] = 31;
Set
Sorted Set
Objects, forms, records

79. Generic
Hash // not associative
List $redis['foo'][] = 'zip';
Set $redis['foo'][] = 'zap';
Sorted Set
Lists, stacks, queues

80. Generic
// No dupes, no order
Hash
shuffle(
List
array_unique($redis['foo'])
Set );
Sorted Set
Relations, stats, matching

81. Generic
Hash // Ordered by *score*
List array_unique($redis['foo']);
Set
Sorted Set
Curing cancer, world peace
Sets but with order or scores

82. Y U NO STOP
LISTING THINGS

83. Generic
Hash
List
Set
Sorted Set

84. Generic
Hash
List
Set
Sorted Set

85. // Code
$client->lpush('news:latest', 'Aliens Attack!');
// Redis
['Aliens Attack!']

86. // 2 hours later...
$client->lpush('news:latest', 'Takei 2016');
// Redis
['Takei 2016', 'Aliens Attack!']

87. // That evening...
$client->lpush('news:latest', 'Eggs = Cancer!');
// Redis
['Eggs = Cancer!', 'Takei 2016', 'Aliens Attack!']

88. Recap

89. // Code
$client->lpush('news:latest', 'Aliens Attack!');
$client->lpush('news:latest', 'Takei 2016');
$client->lpush('news:latest', 'Eggs = Cancer!');
// Redis
['Eggs = Cancer!', 'Takei 2016', 'Aliens Attack!']

90. Getting it back out?

91. Start Index
$client->lrange('news:latest', 0, 1);
En d Index

92. var_dump(
$client->lrange('news:latest', 0, 1)
);
array(2) {
[0]=> string(14) "Eggs = Cancer!"
[1]=> string(10) "Takei 2016"
}

93. That's it.
Really.

95. What about size?

96. $client->lpush('news:latest', 'Free Jetpacks!');
$client->lpush('news:latest', 'Elvis Found!');
$client->lpush('news:latest', 'Takei Wins!');
//...and so on...

97. ltrim

98. $client->ltrim('news:latest', 0, 2);
// Only the three latest stories remain!

99. Cron

100. or simpler...

101. $client->lpush('news:latest', 'Cats Leave Euro');
$client->ltrim('news:latest', 0, 2);

102. Great option for notifications

106. Use Case #5: Tricksy Caching

108. SELECT * FROM Articles
INNER JOIN Authors ON (complicated joins)
-- More joins
WHERE (complicated logic)
LIMIT 0, 20

109. SELECT Articles.id FROM Articles
INNER JOIN Authors ON (complicated joins)
-- More joins
WHERE (complicated logic)

110. $client->lpush('search:a17f3', $ids);

111. $client->lrange('search:a17f3', $limit, $offset);

112. SELECT * FROM Articles
INNER JOIN Authors ON (complicated joins)
-- More joins
WHERE Articles.id IN (1, 2, 3)

114. Use Case #6: Recently Viewed

116. Generic
Hash
List
Set
Sorted Set

117. Generic
Hash
List No duplicates
Set
Sorted Set

118. Generic
Hash
List
Set Needs to be ordered
Sorted Set

119. Generic
Hash
List
Set
Sorted Set Just Right

120. zadd

121. $client->zadd('mykey', 1, 'mydata');
Any integer
t
or floa

122. $client->zadd('recent', 1, '/p/first');

123. $client->zadd('recent', time(), '/p/first');

124. $client->zadd('recent', 1338020901, '/p/first');
$client->zadd('recent', 1338020902, '/p/second');
$client->zadd('recent', 1338020903, '/p/third');
$client->zadd('recent', 1338020904, '/p/fourth');

125. Reading it back out?

126. $client->zrange('recent', 0, 2);
array(3) {
[0]=> string(8) "/p/first"
[1]=> string(9) "/p/second"
[2]=> string(8) "/p/third"
}

127. Reverse
$client->zrevrange('recent', 0, 2);
array(3) {
[0]=> string(9) "/p/fourth"
[1]=> string(8) "/p/third"
[2]=> string(9) "/p/second"
}

128. Duplicates?

129. $client->zadd('recent', 1338020901, '/p/first');
// later...
$client->zadd('recent', 1338020928, '/p/first');

130. $client->zrevrange('recent', 0, 2);
array(3) {
[0]=> string(8) "/p/first"
[1]=> string(9) "/p/fourth"
[2]=> string(8) "/p/third"
}

131. Cool.

132. Other things we can do?

133. $client->zrangebyscore('recent', $low, $high);

134. $yesterday = time()-(60*60*24);
$client->zrangebyscore('recent', $yesterday, '+inf');

135. Intersections

136. zinterstore

137. $client->zinterstore('omg', 2, 'recent', 'favorite');
$client->zrange('omg', 0, 4);

138. Deletion

139. zrem

140. zremrangebyscore

141. $yesterday = time()-(60*60*24);
$client->zremrangebyscore(
'recent', '-inf', $yesterday
);

142. We can do a lot.

143. Scores can be anything.

144. Use Case #7: Sharing Data

145. PHP
Redis
Node.js Python

146. • ActionScript • Java
• C • Lua
• C# • Node.js
• C++ • Objective-C
• Clojure • Perl
• Common Lisp • PHP
• Erlang • Pure Data
• Fancy • Python
• Go • Ruby
• Haskell • Scala
• haXe • Smalltalk
• Io • Tcl

147. $client = new PredisClient();
$client->set('foo', 'bar');

148. var redis = require("redis");
var client = redis.createClient();
client.get("foo", redis.print);

149. Step Further...

150. Pub/Sub

151. $client->publish('bids:42', '$13.01');

152. client.on("message", function (channel, message) {
console.log(channel + "= " + message);
});
client.subscribe("bids:42");
// prints “bids:42= $13.01”

153. yet
Not everyday

154. Use Case #8: Worker Queues

155. $client->lpush('jobs:pending', 'clear_cache');

156. $client->lpush('jobs:pending', '{"do":"email", …}');

157. $client->lpush('jobs:pending', 'job:45');

158. // worker
$client = new PredisClient(array(
'read_write_timeout' => -1
));
do {
$job = $client->brpop('jobs:pending', 0);
doJob($job);
} while(true);

159. This will work.

160. However...

161. Things break.

162. Things break.

163. Clients break.

164. Clients break.

165. Clients crash.

166. do {
$job = $client->brpop('jobs:pending', 0);
doJob($job);
} while(true);

167. Multiple keys is the redis way.

168. 'jobs:pending'
'jobs:working'

169. What we need is: blocking
rpop
lpush

170. brpoplpush
.
No, really

171. do {
$job = $client->brpoplpush(
'jobs:pending', 'jobs:working', 0
);
doJob($job);
} while(true);

172. do {
$job = $client->brpoplpush(
'jobs:pending', 'jobs:working', 0
);
if(doJob($job)) {
$client->lrem('jobs:working', 0, $job);
}
} while(true);

173. Use Case #9: Scripted Commands

174. Use Case #9: Impressing People

175. $client->set('jesse', 'dude');
$client->set('chester', 'sweet');

176. Lua

177. var arguments
local first = redis.call('get', KEYS[1]);
local second = redis.call('get', KEYS[2]);
redis.call('set', KEYS[1], second);
redis.call('set', KEYS[2], first);
return {first, second};

178. // jesse: dude
// chester: sweet
EVAL 'local first...' 2 jesse chester
// jesse: sweet
// chester: dude

179. Eval != Evil
*Offer only applies
in Redis-Land.
.
Void where pedantic

180. Don't over do it.

181. Reusing scripts?

182. SCRIPT LOAD 'local first...'
// 591d1b681192f606d8cb658e1e173e771a90e60e

183. EVAL 'local first...' 2 jesse chester

184. EVALSHA 591d1... 2 jesse chester

185. Sweet.

186. Epilogue

187. Simple = Powerful

188. Fun.

189. Keep it in RAM.

190. Extensible + Ecosystem

191. Great docs.
Use them.

192. Bad for the DB?
Might be good for Redis.

193. Bad for the DB?
Might be good for Redis.

195. IAEA Kotaku
@svdgraaf
Alltheragefaces
QuickMeme

196. http://joind.in/7971