The Big, the Small and the Redis Андрей Савченко Доклад посвящен Redis: одной из самых недооценённых СУБД. Имея, на первый взгляд, не очень большой функционал, при пристальном рассмотрении Redis может дать фору большинству более жирных конкурентов. О том, как правильно его “готовить”, где применять на практике и как вовремя остановиться и будет идти речь в докладе.

1. The big
The small
and The Redis

2. Andrey Savchenko
Github
Twitter
LinkedIn}@ptico
CTO@aejis

3. The world of DBMS

4. Big
• PostgreSQL
• Cassandra
• MongoDB
• and counting…

5. Small
• SQLite
• LevelDB
• Kyoto cabinet
• etc…

6. Redis

7. Redis
• Key-value DB
• High-performant
• Async persistence
• Replication
• Transactions
• Extensions
• Lua-scripting
• Pub/Sub

8. Clients
ActionScript, C, C#, C++, Clojure, Common Lisp,
D, Dart, Emacs Lisp, Erlang, Fancy, Prolog,
Go, Haskell, haXe, Io, Java, Lua, Node.js,
Objective-C, Perl, PHP, Python, Ruby, Rust,
Scala, Scheme, Smalltalk, Tcl

9. Commands
APPEND, AUTH, BGREWRITEAOF, BGSAVE, BITCOUNT, BITOP, BITPOS, BLPOP, BRPOP,
BRPOPLPUSH, CLIENT KILL, CLIENT LIST, CLIENT GETNAME, CLIENT PAUSE, CLIENT
SETNAME, CONFIG GET, CONFIG REWRITE, CONFIG SET, CONFIG RESETSTAT, DBSIZE, DEBUG
OBJECT, DEBUG SEGFAULT, DECR, DECRBY, DEL, DISCARD, DUMP, ECHO, EVAL, EVALSHA,
EXEC, EXISTS, EXPIRE, EXPIREAT, FLUSHALL, FLUSHDB, GET, GETBIT, GETRANGE, GETSET,
HDEL, HEXISTS, HGET, HGETALL, HINCRBY, HINCRBYFLOAT, HKEYS, HLEN, HMGET, HMSET,
HSET, HSETNX, HVALS, INCR, INCRBY, INCRBYFLOAT, INFO, KEYS, LASTSAVE, LINDEX,
LINSERT, LLEN, LPOP, LPUSH, LPUSHX, LRANGE, LREM, LSET, LTRIM, MGET, MIGRATE,
MONITOR, MOVE, MSET, MSETNX, MULTI, OBJECT, PERSIST, PEXPIRE, PEXPIREAT, PFADD,
PFCOUNT, PFMERGE, PING, PSETEX, PSUBSCRIBE, PUBSUB, PTTL, PUBLISH, PUNSUBSCRIBE,
QUIT, RANDOMKEY, RENAME, RENAMENX, RESTORE, ROLE, RPOP, RPOPLPUSH, RPUSH,
RPUSHX, SADD, SAVE, SCARD, SCRIPT EXISTS, SCRIPT FLUSH, SCRIPT KILL, SCRIPT LOAD,
SDIFF, SDIFFSTORE, SELECT, SET, SETBIT, SETEX, SETNX, SETRANGE, SHUTDOWN, SINTER,
SINTERSTORE, SISMEMBER, SLAVEOF, SLOWLOG, SMEMBERS, SMOVE, SORT, SPOP,
SRANDMEMBER, SREM, STRLEN, SUBSCRIBE, SUNION, SUNIONSTORE, SYNC, TIME, TTL,
TYPE, UNSUBSCRIBE, UNWATCH, WATCH, ZADD, ZCARD, ZCOUNT, ZINCRBY, ZINTERSTORE,
ZLEXCOUNT, ZRANGE, ZRANGEBYLEX, ZRANGEBYSCORE, ZRANK, ZREM,
ZREMRANGEBYLEX, ZREMRANGEBYRANK, ZREMRANGEBYSCORE, ZREVRANGE,
ZREVRANGEBYSCORE, ZREVRANK, ZSCORE, ZUNIONSTORE, SCAN, SSCAN, HSCAN, ZSCAN,

10. Documentation

11. Documentation

12. DataTypes
• String
• Hash
• List
• Set
• Sorted set
• HyperLogLog

13. String
SET testkey "Hello"
GET testkey #=> "Hello"
MSET key1 "Hello" key2 "world"
!
SET counter 1
INCR counter
GET counter #=> "2"

14. Hash
HSET test key1 "Hello"
HSET test key2 "World"
HGET test key2 #=> "World"
HGETALL test
#=> "key1" "Hello" "key2" "World"

15. List
RPUSH test "zero"
RPUSH test "one"
RPUSH test "two"
LRANGE test 1 2 #=> "one" "two"

16. Set
SADD users "andrey"
SADD users "dima"
SCARD users #=> 2
SISMEMBER users "andrey" #=> 1
SISMEMBER users "gleb" #=> 0

17. Performance
(MacBook retina 13")
• SET: 67294.75 rps
• GET: 71787.51 rps
• LPUSH: 72202.16 rps
• SADD: 70621.47 rps

18. Persistence and memory
# save <seconds> <changes>
save 900 1
save 300 10
save 60 10000

19. Persistence and memory
# maxmemory <bytes>
maxmemory 1gb

20. Persistence and memory
appendonly yes
# appendfsync always
appendfsync everysec
# appendfsync no

21. Persistence and memory
http://redis.io/topics/persistence
http://antirez.com/post/redis-persistence-demystified.html

22. Use cases

24. Caches, sessions

25. Caches, sessions
Invalidation by time
SET a18f045 "cache content"
EXPIRE a18f045 100

26. Caches, sessions
Invalidation by tags
SET a18b045 "cache content"
SET d98f0c9 "cache content"
SADD tag1 a18b045
SADD tag1 d98f0c9
DEL {{SMEMBERS tag1}}

27. Tags
SADD programming 1 2 3 4 5
SADD ruby 1 4
SADD python 2 3
SADD tdd 1 3
# Posts with both "programming" AND "ruby" tags
SINTER programming ruby # => "1" "4"
!
# Posts with "ruby" OR "python" tags
SUNION ruby python #=> "1" "2" "3" "4"
!
# Posts posts with "ruby" tag but without "tdd" tag
SDIFF ruby tdd #=> "4"
!
# How many posts with "ruby" tag
SCARD ruby #=> 2

28. Job queue
LPUSH worker1 "Job 1"
LPUSH worker1 "Job 2"
LPUSH worker1 "Job 3"
RPOP worker1 #=> "Job 1"
RPOP worker1 #=> "Job 2"

29. Data storage
HSET settings:{id} receive_emails 1
HSET settings:{id} records_per_page 20
HSET settings:{id} preferred_syntax "markdown"
HGETALL settings:{id}

30. Statistics
# Increment counter
INCR posts:{id}
!
# How many views/votes?
GET posts:{id}

31. Statistics
# Increment counter
ZINCRBY posts 1 {id}
!
# How many views/votes?
ZSCORE posts {id}
!
# TOP-10 posts
ZREVRANGE posts 0 9
!
# TOP-10 with views/votes quantity
ZREVRANGE posts 0 9 WITHSCORES

32. Simple graphs
# User Joe adds user Mila to friends
SADD users:{joe}:friends {mila}
SADD users:{mila}:friend_of {joe}
!
# Get Mila's friends
SMEMBERS users:{mila}:friends
!
# Get user Mila's mutual friends
SCARD users:{mila}:friends users:{mila}:friend_of
!
# Get common friends of Mila and Joe
SCARD users:{mila}:friends users:{joe}:friends
!
# Joe is a friend of user Mila?
SISMEMBER users:{mila}:friends {joe}

33. Message bus
# Web-application:
SUBSCRIBE messages
!
# Async jobs server:
SUBSCRIBE jobs
!
# Web-application:
PUBLISH jobs "videos:12:mpeg:ogg"
!
# Async jobs server:
PUBLISH messages "Video encoding #12 finished"

34. Extensions

35. Redis Geo
https://matt.sh/redis-geo
GEOADD kyiv 30.437672 50.440884 "Aejis office"
!
GEORADIUS kyiv 30.437672 50.440884 2 km WITHDISTANCE
#=> "Shulyavska station" "1.61"
"Politech institute" "1.74"
"Aviation university" "0.76"
!
GEORADIUSBYMEMBER kyiv "Aejis office" 2 km
#=> "Shulyavska station"
"Politech institute"
"Aviation university"

36. Redis JSON
https://matt.sh/redis-json
HGETALLJSON settings:{id}
#=> {“receive_emails":1,"records_per_page":20,
"preferred_syntax":"markdown"}
!
JSONWRAP ZREVRANGE posts 0 3 WITHSCORES
#=> {"42":820,"115":760,"110":522}
!
JSONDOCSET users '{"id":42, "name":"John"}'
!
JSONDOCKEYS users
!
JSONDFIELDGET users name

37. Andrey Savchenko @ptico
Attribution:
Thanks!
Ian Barbour https://flic.kr/p/anCQwx (CC-BY-NC-SA 2.0)