Por qué deberías haberle pedido Redis a los Reyes Magos

Todo el mundo está usando Redis, y con motivo: Es rápido, es fácil y es web scale. Pero Redis puede hacer muchas más cosas de las típicas para las que lo usa la comunidad Ruby. En esta charla hablaré sobre lo que se puede hacer con Redis, cómo lo están usando empresas como twitter o pinterest, las cosas que no deberías hacer con redis, algunos patrones interesantes de uso, y cómo lo estamos usando en teowaki para resolver un montón de problemas.
Javier Ramírez (@supercoco9)

Desarrollador web, soñador y en general una persona feliz. Interesado en todo lo que tenga que ver con Internet y cómo está cambiando nuestra cultura y nuestra sociedad. Fundador de teowaki.com, donde intentamos hacer más felices a los desarrolladores ayudándoles a compartir información técnica, rumores y lifehacks con sus amigos desarrolladores.

Vivo en Londres, pero puedes encontrarme en javier-ramirez.com y como @supercoco9 en twitter.

Transcript

1. javier ramirez @supercoco9 Por qu deber as haberle é í pedido Redis a los Reyes Magos
3. In the beginner's mind there are many possibilities, in the expert's mind there are few. Shunryu Suzuki javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
4. myth: the bottleneck javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
5. Intel(R) Xeon(R) CPU E5520 @ 2.27GHz (with pipelining) $ ./redis-benchmark -r 1000000 -n 2000000 -t get,set,lpush,lpop -P 16 -q SET: 552,028 requests per second GET: 707,463 requests per second LPUSH: 767,459 requests per second LPOP: 770,119 requests per second Intel(R) Xeon(R) CPU E5520 @ 2.27GHz (without pipelining) $ ./redis-benchmark -r 1000000 -n 2000000 -t get,set,lpush,lpop -q SET: 122,556 requests per second GET: 123,601 requests per second LPUSH: 136,752 requests per second LPOP: 132,424 requests per second javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
6. myth: Redis is just like memcached javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
7. myth: Redis is for queues javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
8. open source, BSD licensed, advanced key-value store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets and sorted sets. http://redis.io started in 2009 by Salvatore Sanfilippo @antirez 103 contributors at https://github.com/antirez/redis javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
9. hacker meets thinker* *@janogonzalez and @advi inspired slide javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
10. The Redis Manifesto 1.A DSL for Abstract Data Types 2.Memory storage is #1 3.Fundamental data structures for a fundamental API 4.Two levels of API 5.Code is like a poem; it's not just something we write to reach some practical result 6.We're against complexity 7.We optimize for joy javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
11. connecting to redis javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
12. basics: setting and getting javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
13. basics: lists javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
14. basics: hashes javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
15. basics: sets cool example about sunionstore http://robots.thoughtbot.com/post/46335890055/redis-set-intersection-using-sets-to-filter-data javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
16. Redis as a PUBSUB system javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
17. Redis keeps everything in memory all the time javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
18. Persistance: RDB Compact binary format Saves snapshots every few minutes Good for backups and synchronizing If Redis crashes, a few minutes worth of data will be lost javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
19. Durability: AOF Log text format Configurable durability Large file, can slow down startup If Redis crashes, typically one second of data could be lost javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
20. replication & scaling out one master, several read-only slaves sharding Twemproxy & redis cluster javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
21. atomicity single threaded, so no concurrency problems transactions and lua scripts to run multiple operations atomically javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
22. Scripting with lua You can use Lua for scripting Redis when you need to atomically execute a sequence of commands in which the output of a command is used as input for another It reduces the need to use complex lock mechanisms and simplifies dependencies between clients You can even extend the functionality of Redis by using Lua scripts javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
23. what's being used for javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
24. twitter Every time line (800 tweets per user) is on redis 5000 writes per second avg 300K reads per second javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
25. twitter user info from gizmoduck (memcached) user id tweet id metadata write API (from browser or client app) rpushx to Redis tweet info from tweetypie (memcached + mysql) your twitter timeline javier ramirez @supercoco9 https://teowaki.com madrid rb 2013 fanout (flockDB) one per follower
26. pinterest object graph from mysql+memcached to redis 30% save on IOps javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
27. per user Redis SortedSet, with timestamp as the score, is used to store the users followed explicitly. Redis SortedSet, with timestamp as the score, is used to store the users followed implicitly Redis SortedSet, with timestamp as the score, is used to store the user’s explicit followers Redis SortedSet, with timestamp as the score, is used to store the user’s implicit followers Redis Set is used to store boards followed explicitly Redis Set is used to store boards unfollowed explicitly per board Redis Hash is used to store a board’s explicit followers Redis Set is used to store a board’s explicit unfollowers javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
28. viacom Object dependency graph. Cache on steroids Redis as a queue for background jobs Activity tracking and view counts buffering before saving to mysql Lua script working on a slave to recalculate ranking and popularity of contents, then send the data to master. The new process takes 1/60th less than the old one in mysql javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
29. openredis redis as a service on AWS serving over 1000 customers with a single machine javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
30. when things go wrong javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
31. the instagram case moving from redis to cassandra: 75% savings on servers lesson learnt: know when redis is not appropriate javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
32. the twilio case credit card hell lesson learnt: know what you are doing. Don't change config on the fly javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
33. how teowaki is using redis javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
34. Abusing sidekiq/resque keep track of every activity in the system, even if you don't need them all right now: - every page view - every API request - every time a record is created/updated/deleted benefits: - highly decoupled system - easier to divide into services - you can add behaviour without changing your app javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
35. intermediate cache * As a very fast lightweight storage for analytics data before sending them to our google bigquery based solution * As a cache for AR attributes frequently “plucked” or included and plucked (names, nicknames, guids, delegated or included model names...) javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
36. Some of our uses of Lua Expiring attributes inside a Redis hash Inserting notifications into a list only if there are not pending notifications from the same user for the same scope Paginating a list by an attribute Manipulating JSON directly at the Redis layer javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
37. counters Atomic counters can be safely invoked concurrently from anywhere, so you can implement “like” features, global sequences or usage monitoring systems in highly concurrent applications for free. You can share your counters with any other internal application and still be sure they won't collide. javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
38. Temporary data Redis allows us to self expire keys after a time has passed. You can use this mechanism for a simple cache If you operate on a key with expiration time, you can change its value and still keep the expiration going. By combining a decrementing counter with an expiration time, implementing usage quotas is trivial Also, you can inspect which keys you have in your server efficiently using SCAN commands javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
39. bloom filters bloom filter: space-efficient probabilistic data structure that is used to test whether an element is a member of a set. False positive matches are possible, but false negatives are not. Redis bit operations make easy to implement bloom filters We are using bloom filters for checking uniqueness of user names and reserved words without going to postgresql javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
40. nginx + lua + redis apache + mruby + redis Multiple levels of cache by using Redis on the webserver/ middleware layer http://wiki.nginx.org/HttpRedis https://github.com/jodosha/redis-store javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
41. summarizing * Redis is more powerful than it seems * Very fast, easy to use, simple, good documentation * In-memory data structures, distributed, shared and persisted * Good as data store, intermediate data store, cache or queue * Lots of use cases, both in huge and smaller systems You should probably use it a lot more javier ramirez @supercoco9 https://teowaki.com madrid rb 2013
42. Find related links at https://teowaki.com/teams/javier-community/link-categories/redis Gracias! ¡ Javier Ramírez @supercoco9 madrid rb 2013