Talk given at NodeMTL #5

1. Redis and its many uses
Christian Joudrey - @cjoudrey

2. ‘‘Redis is an open source,
advanced key-value store.
’’

3. Key-value what?!

4. SET name "fido"
GET name
=> "fido"

5. EXPIRE name 120

6. So it's like
memcached?

7. Atomic operations

8. SET count 0
INCR count
=> 1

9. Ordered lists

10. LPUSH friends "Tom"
LPUSH friends "Sam"
LLEN friends
=> 2

11. LPUSH RPUSH
Sam Tom

12. LRANGE friends 0 0
=> ["Sam"]
LRANGE friends 0 -1
=> ["Sam", "Tom"]

13. Sets, Hashes,
Sorted Sets

14. Save to disk

15. Download it
http://redis.io/download
... and try it ...
$ redis-cli
redis> SET name "Chris"
OK
redis> GET name
"Chris"

16. What about node?!

17. GitHub
http://git.io/redis
... or via npm ...
$ npm install redis

18. Use case #1:
Caching

19. var redis = require('redis'),
client = redis.createClient();
function getSomeValue (callback) {
client.get('someVal', function (err, val) {
if (val) return callback(null, val);
// Do call directly to Db
// and cache result.
});
};

20. Use case #2:
Session store

21. var app = require('express').createServer();
var RedisStore = require('connect-redis')(express);
app.use(express.session({
secret: 'keyboard cat', store: new RedisStore
}));
app.get('/', function(req, res){
res.send('hello world');
});
app.listen(3000);
http://expressjs.com/guide.html#session-support

22. Use case #3:
Pub/Sub

23. Chat Chat
Server Server
Load
Balancer

24. Use case #4:
Job Queue

25. i.e.:
Image resize API

26. 1) Download image
2) Resize image with GD
Node
Server
GET /image_resize?url=http://...

27. orker Job
Resize
Queue
Workers
1) Download image Node
2) Resize image with GD
Server
GET /image_resize?url=http://...

28. Kue
https://github.com/learnboost/kue

29. There's a lot more!
11 Common Web Use Cases Solved in Redis
http://bit.ly/pgDmXn

30. Questions? :)