Redis for the Everyday Developer

As presented at Northeast PHP. #nephp

More than some arcane NoSQL tool, Redis is a simple but powerful swiss army knife you can begin using today.

This talk introduces Redis and focuses on using it to cleanly solve common problems. Along the way, you'll learn how Redis can be used as an alternative to several common PHP tools.

Transcript

1. Ross Tuck Redis For The Everyday Developer Northeast PHP August 11th, #nephp
2. Who Am I?
3. Ross Tuck
4. Team Lead at Ibuildings Codemonkey HTTP nut Hat guy
6. @rosstuck
7. Boring.
9. NoSQL
10. NoNoSQL
11. Evaluation
12. • Created by Salvatore Sanfilippo ( @antirez ) • Sponsored by VMware • 3 years old • redis.io
13. “Redis is an open source, advanced key-value store.”
14. “It is often referred to as a data structure server...”
15. Defancypants
16. Server A Server B Redis
17. In-Memory
18. In-Memory
19. The Cool Stuff
20. Fast.
21. Demo.
22. Oh wait, it's already done.
23. 120,000~ ops per sec
24. Flexible.
25. (optionally) Persistent.
26. Replication Pub/Sub Scripting Transactions Slices Dices Makes julienne fries
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 \Predis\Client();
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. Use Case #2: Session Storage
52. You already know it.
53. Use Case #3: Hit Counters
55. increment
56. $client->incr('page:42:views'); $client->incr('page:42:views'); $client->incr('page:42:views'); // 1 // 2 // 3
57. Redis is hard ;)
58. How is this better?
60. Fast?
61. 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
62. Fast enough.
63. $client->incr('cookies:eaten'); $client->incrBy('cookies:eaten', 2); $client->incrByFloat('cookies:eaten', 0.5); version 2.6+
64. Use Case #4: Latest News
66. “It is often referred to as a data structure server...”
67. “...since keys can contain strings, hashes, lists, sets and sorted sets.”
68. $redis = array();
69. Generic Hash List Set Sorted Set
70. Generic Hash List Set Sorted Set // strings and numbers $redis['ross:mood'] = "happy"; $redis['foo'] = 9;
71. Generic Hash List Set Sorted Set // associative array $redis['foo']['name'] = 'Bob'; $redis['foo']['age'] = 31; Objects, forms, records
72. Generic Hash List Set Sorted Set // not associative $redis['foo'][] = 'zip'; $redis['foo'][] = 'zap'; Lists, stacks, queues
73. Generic Hash List Set Sorted Set // No dupes, no order shuffle( array_unique($redis['foo']) ); Relations, stats, matching
74. Generic Hash List Set Sorted Set // Ordered by *score* array_unique($redis['foo']); Curing cancer, world peace Sets but with order or scores
75. Y U NO STOP Y U NO STOP LISTING THINGS LISTING THINGS
76. Generic Hash List Set Sorted Set
77. Generic Hash List Set Sorted Set
78. // Code $client->lpush('news:latest', 'Aliens Attack!'); // Redis ['Aliens Attack!']
79. // Redis ['Takei 2012', 'Aliens Attack!'] // 2 hours later... $client->lpush('news:latest', 'Takei 2012');
80. // That evening... $client->lpush('news:latest', 'Eggs = Cancer!'); // Redis ['Eggs = Cancer!', 'Takei 2012', 'Aliens Attack!']
81. Recap
82. // Code $client->lpush('news:latest', 'Aliens Attack!'); $client->lpush('news:latest', 'Takei 2012'); $client->lpush('news:latest', 'Eggs = Cancer!'); // Redis ['Eggs = Cancer!', 'Takei 2012', 'Aliens Attack!']
83. Getting it back out?
84. $client->lrange('news:latest', 0, 1); End Index Start Index
85. var_dump( $client->lrange('news:latest', 0, 1) ); array(2) { [0]=> string(14) "Eggs = Cancer!" [1]=> string(10) "Takei 2012" }
86. That's it. Really.
88. What about size?
89. $client->lpush('news:latest', 'Free Jetpacks!'); $client->lpush('news:latest', 'Elvis Found!'); $client->lpush('news:latest', 'Takei Wins!'); //...and so on...
90. ltrim
91. $client->ltrim('news:latest', 0, 2); // Only the three latest stories remain!
92. Cron
93. or better...
94. $client->lpush('news:latest', 'Cats Leave Euro'); $client->ltrim('news:latest', 0, 2);
95. Great option for notifications
100. SELECT * FROM Articles INNER JOIN Authors ON (complicated joins) -- More joins WHERE (complicated logic) LIMIT 0, 20
101. SELECT Articles.id FROM Articles INNER JOIN Authors ON (complicated joins) -- More joins WHERE (complicated logic)
102. $client->lpush('search:a17f3', $ids);
103. $client->lrange('search:a17f3', $limit, $offset);
105. Use Case #5: Recently Viewed
107. Generic Hash List Set Sorted Set
108. Generic Hash List Set Sorted Set No duplicates
109. Generic Hash List Set Sorted Set Needs to be ordered
110. Goldilocks Just Right Generic Hash List Set Sorted Set
111. zadd
112. $client->zadd('mykey', 1, 'mydata'); Any integer or float
113. $client->zadd('recent', 1, '/p/first');
114. $client->zadd('recent', time(), '/p/first');
115. $client->zadd('recent', 1338020901, '/p/first'); $client->zadd('recent', 1338020902, '/p/second'); $client->zadd('recent', 1338020903, '/p/third'); $client->zadd('recent', 1338020904, '/p/fourth');
116. Reading it back out?
117. array(3) { [0]=> string(8) "/p/first" [1]=> string(9) "/p/second" [2]=> string(8) "/p/third" } $client->zrange('recent', 0, 2);
118. $client->zrevrange('recent', 0, 2); Reverse array(3) { [0]=> string(9) "/p/fourth" [1]=> string(8) "/p/third" [2]=> string(9) "/p/second" }
119. Duplicates?
120. $client->zadd('recent', 1338020901, '/p/first'); // later... $client->zadd('recent', 1338020928, '/p/first');
121. array(3) { [0]=> string(8) "/p/first" [1]=> string(9) "/p/fourth" [2]=> string(8) "/p/third" } $client->zrevrange('recent', 0, 2);
122. Cool.
123. Other things we can do?
124. $client->zrangebyscore('recent', $low, $high);
125. $yesterday = time()-(60*60*24); $client->zrangebyscore('recent', $yesterday, '+inf');
126. Intersections
127. zinterstore
128. $client->zinterstore('omg', 2, 'recent', 'favorite'); $client->zrange('omg', 0, 4);
129. zrem
130. zremrangebyscore
131. $yesterday = time()-(60*60*24); $client->zremrangebyscore( 'recent', '-inf', $yesterday );
132. We can do a lot.
133. Scores can be anything.
134. Use Case #6: Sharing Data
135. Redis PHP Node.js Python
136. • ActionScript • C • C# • C++ • Clojure • Common Lisp • Erlang • Fancy • Go • Haskell • haXe • Io • Java • Lua • Node.js • Objective-C • Perl • PHP • Pure Data • Python • Ruby • Scala • Smalltalk • Tcl
137. $client = new \Predis\Client(); $client->set('foo', 'bar');
138. var redis = require("redis"); var client = redis.createClient(); client.get("foo", redis.print);
139. Step Further...
140. Pub/Sub
141. $client->publish('broadcast', 'batkitty');
142. client.on("message", function (channel, message) { console.log(channel + ": " + message); }); client.subscribe("broadcast"); // prints “broadcast: batkitty”
143. Not everyday yet
144. Use Case #7: Worker Queues
145. $client->lpush('jobs:pending', 'clear_cache');
146. $client->lpush('jobs:pending', '{"do":"email", …}');
147. $client->lpush('jobs:pending', 'job:45');
148. // worker $client = new \Predis\Client(array( 'read_write_timeout' => -1 )); do { $job = $client->brpop('jobs:pending', 0); doJob($job); } while(true);
149. This will work.
150. However...
151. Things break.
152. Things break.
153. Clients break.
154. Clients break.
155. Clients crash.
156. do { $job = $client->brpop('jobs:pending', 0); doJob($job); } while(true);
157. Multiple keys is the redis way.
158. 'jobs:pending' 'jobs:working'
159. What we need is: blocking rpop lpush
160. brpoplpush No, really.
161. do { $job = $client->brpoplpush( 'jobs:pending', 'jobs:working', 0 ); doJob($job); } while(true);
162. do { $job = $client->brpoplpush( 'jobs:pending', 'jobs:working', 0 ); if(doJob($job)) { $client->lrem('jobs:working', 0, $job); } } while(true);
163. Epilogue
164. Simple = Powerful
165. Fun.
166. Keep it in RAM.
167. Redis 2.6 will be amazing.
168. Great docs. Use them.
169. Bad for the DB? Might be good for Redis.
170. Bad for the DB? Might be good for Redis.
172. @svdgraaf QuickMeme IAEA Kotaku
173. http://joind.in/6829