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getting Started
If you have not been exposed Redis, please read [] entry to the master Redis-
The basic data structure Redis
Here we briefly review the case, remember that common enough, remember the visit the official website.
Redis API
Spoken API
keys 、del 、dbsize 、expire (ttl、persist)、exists、type…….
Time complexity is O (1)
strings\ hash\list\set\zset
Strings
SET key value //存入字符串键值对
MSET key value [key value ...] //批量存储字符串键值对
SETNX key value //存入一个不存在的字符串键值对
GET key //获取一个字符串键值
MGET key [key ...] //批量获取字符串键值
DEL key [key ...] //删除一个键
EXPIRE key seconds //设置一个键的过期时间(秒)
原子加减
INCR key //将key中储存的数字值加1
DECR key //将key中储存的数字值减1
INCRBY key increment //将key所储存的值加上increment
DECRBY key decrement //将key所储存的值减去decrement
Hash
HSET key field value //存储一个哈希表key的键值
HSETNX key field value //存储一个不存在的哈希表key的键值
HMSET key field value [field value ...] //在一个哈希表key中存储多个键值对
HGET key field //获取哈希表key对应的field键值
HMGET key field [field ...] //批量获取哈希表key中多个field键值
HDEL key field [field ...] //删除哈希表key中的field键值
HLEN key //返回哈希表key中field的数量
HGETALL key //返回哈希表key中所有的键值
HINCRBY key field increment //为哈希表key中field键的值加上增量increment
List
LPUSH key value [value ...] //将一个或多个值value插入到key列表的表头(最左边)
RPUSH key value [value ...] //将一个或多个值value插入到key列表的表尾(最右边)
LPOP key //移除并返回key列表的头元素
RPOP key //移除并返回key列表的尾元素
LRANGE key start stop //返回列表key中指定区间内的元素，区间以偏移量start和stop指定
BLPOP key [key ...] timeout //从key列表表头弹出一个元素，若列表中没有元素，阻塞等待 timeout秒,如果timeout=0,一直阻塞等待
BRPOP key [key ...] timeout //从key列表表尾弹出一个元素，若列表中没有元素，阻塞等待 timeout秒,如果timeout=0,一直阻塞等待
Set
Set常用操作
SADD key member [member ...] //往集合key中存入元素，元素存在则忽略，
若key不存在则新建
SREM key member [member ...] //从集合key中删除元素
SMEMBERS key //获取集合key中所有元素
SCARD key //获取集合key的元素个数
SISMEMBER key member //判断member元素是否存在于集合key中
SRANDMEMBER key [count] //从集合key中选出count个元素，元素不从key中删除
SPOP key [count] //从集合key中选出count个元素，元素从key中删除
Set运算操作
SINTER key [key ...] //交集运算
SINTERSTORE destination key [key ..] //将交集结果存入新集合destination中
SUNION key [key ..] //并集运算
SUNIONSTORE destination key [key ...] //将并集结果存入新集合destination中
SDIFF key [key ...] //差集运算
SDIFFSTORE destination key [key ...] //将差集结果存入新集合destination中
token
ZSet常用操作
ZADD key score member [[score member]…] //往有序集合key中加入带分值元素
ZREM key member [member …] //从有序集合key中删除元素
ZSCORE key member //返回有序集合key中元素member的分值
ZINCRBY key increment member //为有序集合key中元素member的分值加上increment
ZCARD key //返回有序集合key中元素个数
ZRANGE key start stop [WITHSCORES] //正序获取有序集合key从start下标到stop下标的元素
ZREVRANGE key start stop [WITHSCORES] //倒序获取有序集合key从start下标到stop下标的元素
Zset集合操作
ZUNIONSTORE destkey numkeys key [key ...] //并集计算
ZINTERSTORE destkey numkeys key [key …] //交集计算
Scenarios
Strings
Single-value cache
SET key value
GET key
Object Caching
1) SET user:1 value (json格式数据)
2) MSET user:1:name artisan user:1:balance 1888
MGET user:1:name user:1:balance
Distributed Lock
SETNX product:10001 true //返回1代表获取锁成功
SETNX product:10001 true //返回0代表获取锁失败
。。。执行业务操作
DEL product:10001 //执行完业务释放锁
SET product:10001 true ex 10 nx //防止程序意外终止导致死锁
counter
INCR article:judge:{文章id}
GET article: judge:{文章id}
Forwarding comment
How to cluster environments concurrently access the same article guarantee thread safety
redis threaded atomicity
Web cluster shared session
spring session + redis achieve shared session
spring session itself is to use as an external storage redis
Global Distributed System serial number
INCRBY orderId 1000
Every time get 1000 into memory, VS are going to take every one redis
Multi-table N, N multiple concurrent, N multi-scene using redis
Node hung it does not matter, nothing more than a waste of id
Hash
Object Caching
HMSET user {userId}:name artisan {userId}:balance 1888
HMSET user 1:name artisan 1:balance 1888
HMGET user 1:name 1:balance
Timeout for the key, not for the field
to avoid the big key
Electricity supplier shopping cart
1) the user id to Key
2) for the item id of Field
. 3) the number of items of value
• Operating cart
- Add product
hset cart:1001 10088 1 - Increase the number
hincrby cart:1001 10088 1 - The total number of goods
hlen cart:1001 - Delete item
hdel cart:1001 10088 - Gets cart all goods
hgetall cart:1001
List
Common data structures
Stack(栈) = LPUSH + LPOP FILO
Queue(队列）= LPUSH + RPOP
Blocking MQ(阻塞队列）= LPUSH + BRPOP ( 会阻塞其他消息，如果使用，使用单独的Redis)
Micro channel - subscribe message number
For example, I am concerned about the public number, the message sent by these numbers how public display?
For example
1) A 23:00 No release public article, the message ID is 10018
LPUSH msg:{我的-ID} 10018
2) B 23:05 article published public number, the message ID is 10086
LPUSH msg:{我的-ID} 10086
3) C 23:30 article published public number, the message ID is 10099
LPUSH msg:{我的-ID} 10099
3) Check the latest concern of the public announcement No.
LRANGE msg:{我的-ID} 0 5
I have to put this queue, lpush release from the left
C article article id id A B of article id
Get, certainly in chronological flashback row
LRANGE msg:{我的-ID} start stop
Set
Thumbs up, collection, label
- like
SADD like:{消息ID} {用户ID}
- Cancel thumbs up
SREM like:{消息ID} {用户ID}
- Check whether the user is past Chan
SISMEMBER like:{消息ID} {用户ID}
- Users get a list of thumbs up
SMEMBERS like:{消息ID}
- Users get thumbs up
SCARD like:{消息ID}
lottery
Click added lottery participation set
the SADD userlD} {Key
2) See all users participate in the lottery
SMEMBERS Key
. 3) were extracted count winners
SRANDMEMBER key [count] / SPOP key [count]
One two three prize draw Removes SPOP
Common interest, mutual friend. . .
Application collection operation
SINTER set1 set2 set3 -> { c }
SUNION set1 set2 set3 -> { a,b,c,d,e }
SDIFF set1 set2 set3 -> { a } 以第一个集合为基准，减去后面的集合所有元素
Abc - bcd cde ---> a 第一个集合不存在的不算
token
Trending
1) Click on News
ZINCRBY hotNews:20200307 1 fujian 【score加1 】
2) shows the date of the top ten ranking
ZREVRANGE hotNews:20200307 0 10 WITHSCORES
3) calculate the seven search list
ZUNIONSTORE hotNews:20200301-20200307 7
hotNews:20200301 hotNews:202000302... hotNews:202000307
4) shows seven top ten ranking
ZREVRANGE hotNews:20200301-20200307 0 10 WITHSCORES
