Shulou(Shulou.com)06/02 Report--

Introduction to Redis

Redis is an open source log database written in ANSI C language, complies with BSD protocol, supports network, can be memory-based and persistent, Key-Value database, and provides API in multiple languages.

It is often called a data structure server because the value can be of types such as String, Map, list, sets, and sorted sets.

Redis installs $wget http://download.redis.io/releases/redis-5.0.5.tar.gz$ tar xzf redis-5.0.5.tar.gz$ cd redis-5.0.5$ make to start Redis in the background to modify the Redis.conf file

Daemonize on

Modify to

Daemonize yes starts Redissrc/redis-server redis.conf

Boot and start Redis

Execute the installation script, which is always the default.

. / utils/install_server.sh

Mv / etc/init.d/redis_6379 / etc/init.d/redis set Redis password vim / etc/redis/6379.confrequirepass redispassservice redis restart

Re-connection discovery requires entering a password

Redis command global command get key keys pattern

Keys also supports wildcards

127.0.0.1 OK127.0.0.1:6379 > set we "hello" OK127.0.0.1:6379 > keys * 1) "we" 127.0.0.1 OK127.0.0.1:6379 > set name wangerOK127.0.0.1:6379 > keys name1) "name" 127.0.0.1 > keys * 1) "name" 2) "we"

The keys command traverses all the keys in Redis, and when there are too many keys, it will affect the performance of Redis.

Delete key del key1 key2..

For example:

127.0.0.1) keys * 1) "qwe" 2) "asd" 3) "we" 127.0.0.1 > del asd qwe (integer) 2127.0.1 > keys * 1) "we" determines whether there is an exists key1 key2 in the key.

For example:

127.0.0.1 exists we (integer) 1127.0.0.1 exists name (integer) 0127.0.0.1 exists name > set qwe 2OK127.0.0.1:6379 > exists we qwe (integer) 2127.0.1 > exists we name (integer) 1 get the total number of keys dbsize

For example:

127.0.0.1 keys 6379 > dbsize (integer) 2127.0.0.1 keys * 1) "qwe" 2) "we" gets the data type type key of the key

For example:

127.0.0.1 lpush list1 6379 > type westring127.0.0.1:6379 > integer 123 (integer) 3127.0.0.1 integer 6379 > type list1list sorts the elements of lists, collections, ordered collections sort key [BY pattern] [LIMIT offset count] [GET pattern [GET pattern...]] [ASC | DESC] [ALPHA] [STORE destination]

For example:

127.0.0.1 lrange list 0-11) "5" 2) "7" 3) "2" 4) "4" 5) "3" 6) "1" sort list desc limit 051) "7" 2) "5" 3) "4" 4) "4" 5) "3" 127.0.1 3sort list2 desc limit 0 5 alpha1) "zxc" 2) "qwe" 3) "asd" empty the database flushdb / / clear the current database flushall / / empty all databases

For example:

127.0.0.1 set 6379 [11] > get a 1OK127.0.0.1:6379 [11] > get a "1" 127.0.0.1 get 6379 [11] > flushdbOK127.0.0.1:6379 [11] > get a (nil) moves the specified key to another database move key db

For example:

127.0.0.1 set [11] > move a 1OK127.0.0.1:6379 [11] > move a 2 (integer) 1127.0.1 move [11] > select 2OK127.0.0.1:6379 [2] > move a "1" string

String type is the most basic data structure of Redis. String type is the basis of several other data types. It can store any form of string, including binary data.

Set the value set key value [EX seconds] [PX milliseconds] [NX | XX] get keynx: the key must not exist before it can be successfully set and used to add. Xx: in contrast to nx, the key must exist before it can be successfully set for update

For example:

127.0.0.1 wanger 6379 > set name wangerOK127.0.0.1:6379 > get name "wanger" 127.0.0.1 wanger 6379 > setnx name wanger (integer) 0127.0.1 purl 6379 > set name wang xxOK batch setting value mset key1 value1 key2 value2.. mget key1 key2

For example:

127.0.0.1 key2 2OK127.0.0.1:6379 6379 > mset key1 1 key2 2OK127.0.0.1:6379 > mget key1 key21) "1" 2) "2" pair of keys self-increasing and decreasing incr keydecr key

For example:

127.0.0.1 incr key1 (integer) 2127.0.0.1 incr key2 (integer) 3127.0.0.1 incr key2 > get key1 "2" 127.0.0.1 incr key2 6379 > get key2 "3" 127.0.1purl 6379 > get we "hello" 127.0.1purl 6379 > incr we (error) ERR value is not an integer or out of range127.0.0.1:6379 > decr key1 (integer) 1127.0.1purl 6379 > decr key2 (integer) 2 added value append key value

For example:

127.0.0.1 append key world 6379 > append key hello (integer) 5127.0.0.1 append key world (integer) 10127.0.1 append key world 6379 > get key "helloworld" get string length strlen key

For example:

127.0.0.1 get key 6379 > strlen key (integer) 10127.0.0.1 strlen key 6379 > set name "Wang er" OK127.0.0.1:6379 > strlen name (integer) 6 sets and gets the string setrange key offset valuegetrange key start end of the specified location

For example:

127.0.0.1 OK127.0.0.1:6379 > SET key1 "Hello World" OK127.0.0.1:6379 > setrange key1 6 "Redis" (integer) 11127.0.0.1 Redis > get key1 "Hello Redis" 127.0.0.1 > getrange key1 6 12 "Redis" string object Encoding

There are three internal encodings of string types:

A long integer of int:8 bytes. Embstr: a string less than or equal to 39 bytes. Raw: a string greater than 39 bytes.

For example:

127.0.0.1 set short qweasdOK127.0.0.1:6379 > object encoding num "int" 127.0.0.1 int 6379 > set short qweasdOK127.0.0.1:6379 > object encoding short "embstr" 127.0.0.1 set short qweasdOK127.0.0.1:6379 > set raw "when you love me I have lost of plot wow wow" OK127.0.0.1:6379 > object encoding raw "raw" list

The Redis list can store an ordered list of strings, which is internally implemented using a two-way linked list. As a common data structure, a two-way linked list has two pointers for each data node of the two-way linked list, pointing to the successor node and the precursor node, respectively. Starting from any node in the two-way linked list, you can easily access its precursor and successor nodes, so the closer the elements are to both ends, the faster you get.

Insert elements from the left and right sides or insert data lpush key value1 value2 value3rpush key value1 value2 value3linsert key BEFORE from before and after an element | AFTER pivot value

For example:

127.0.0.1 (integer) 4127.0.0.1 (integer) 4127.0.0.1) lrange names 041) "4" 2) "3" 3) "2" 4) "1" 127.0.1 (integer) 4127.0.1 (integer) 4127.0.1) integer) "1" 2) "2" 3) "3" 4) "4" 127.0.0.1 rpush nums 6379 > linsert nums before 2 5 (integer) 5127.0.1 lpop keyrpop key > lrange nums 0 51) "1" 2) "5" 3) "2" 4) "3" 5) "4" removes the element lpop keyrpop key from both ends of the list

For example:

127.0.0.1rpop nums 6379 > lrange nums 051) "1" 2) "5" 3) "2" 4) "3" 5) "4" 127.0.0.1 rpop nums "1" 127.0.0.1 lindex key index > lrange nums 051) "5" 2) "2" 3) "3" gets the element lindex key index at a given position

For example:

127.0.0.1lindex nums 6379 > lrange nums 051) "5" 2) "2" 3) "3" 127.0.0.1 lrange key start stop > lindex nums 2 "3" 127.0.0.1 lrange key start stop > lindex nums 1 "2" 127.0.0.1vet 6379 > lindex nums-1 "3" gets the element lrange key start stop in a given range

For example:

127.0.0.1llen key 6379 > lrange nums 0 11) "5" 2) "2" 127.0.0.1 llen key > lrange nums 0 21) "5" 2) "2" 3) "3" get list length llen key

For example:

127.0.0.1lrem key count valuecount 6379 > lrange nums 031) "5" 2) "2" 3) "3" 127.0.0.1 integer 6379 > lrem key count valuecount (integer) 3 removes the value lrem key count valuecount > 0 from the list: deletes the number of elements with the value value moved from beginning to end. Count

Lrange mylist 0 101) "1" 2) "2" 3) "3" 4) "4" 5) "5" 6) "2" 7) "3" 8) "4" 9) "5" 10) "5" 127.0.0.1) lrem mylist 1 5 (integer) 1127.0.1) lrange mylist 0101) "1" 2) "2" 3) "3" 4) "4" 5) "2" 6) "3" 7) "4" 8) "5" 9) "5" 127.0.0.1 lrange mylist 6379 > lrem mylist-2 (integer) 2127.0.1 lrange mylist 0101) 1 "2) 2" 3) 3) 4 "5) 2" 6) "3" 7) "4" 127.0.1 Suzhou 6379 > lrem mylist 02 (integer) 2127.0.0. 1RV 6379 > lrange mylist 0111) "1" 2) "3" 3) "4" 4) "3" 5) "4" modify the element lset key index value of the specified index

For example:

127.0.0.1 lrange mylist 6379 > lrange mylist 0 61) "1" 2) "3" 3) "4" 4) "3" 5) "4" 127.0.1 5OK127.0.0.1:6379 > lrange mylist 0 61) "1" 2) "5" 3) "4" 4) "3" 5) "4" blocking operation

Blpop and brpop are blocking versions of lpop and rpop, respectively, and function is similar. When the list is empty, blocking occurs. Timeout can define the blocking time, and when timeout is 0, it will remain blocked until an element is added to the list in another client.

Blpop key1 key2 timeoutbrpop key1 key2 timeout

For example:

Lrange list2 041) "4" 2) "3" 3) "2" 127.0.0.1 blpop list1 list2 041) "8" 2) 7 "127.0.0.1 blpop list1 list2 01)" list1 "2)" 8 "127.0.0.1 brpop list1 list2 01)" list1 "2)" 7 "127.0.0.1 > brpop list1 list2 01)" list2 " 2) "2" 127.0.0.1brpop list1 list2 6379 > brpop list1 list2 01) "list2" 2) "3" 127.0.0.1 brpop list1 list2 6379 > brpop list1 list2 01) "list2" 2) "4" 127.0.0.1 brpop list1 list2 01) "list2" 2) "1" (18.49s) execute 127.0.0.1 6379 > lpush list2 1 (integer) 1 list internal coding ziplist (compressed list) on another client ): use ziplist-encoded linkedlist (linked list) when all string elements saved by list elements are less than 64 bytes long and the number of elements is less than 512: when the list type cannot meet either of the two conditions Redis will use linkedlist as the internal implementation of the list quicklist is a two-way linked list of ziplist, a two-way linked list is made up of multiple nodes (Node), and each node of the quicklist is a ziplist.

Refer to Zhang Tielei http://zhangtielei.com/posts/blog-redis-quicklist.html

Hash

A hash is a mapping made up of fields associated with a value. Fields and values are strings, and the mapping in the hash type is called field-value

Set the value hset key field valuehget key field

For example:

127.0.0.1 hset ha name wanger 6379 > hget ha name (integer) 1127.0.0.1 hget ha name batch setting value hmset key field1 value1 field2 value2hmget key field1 field2

For example:

127.0.0.1 wanger 6379 > hmset he name wanger sex nanOK127.0.0.1:6379 > hmget he name sex1) "wanger" 2) "nan" delete fieldhdel key field1 field2

For example:

127.0.0.1 field 6379 > hdel he name (integer) 1127.0.0.1 hget he name (nil) get the number of field hlen key

For example:

127.0.0.1 hgetall key 6379 > hmset he name wanger sex nan age 18OK127.0.0.1:6379 > hlen he (integer) 3 get all fields and values hgetall key in the hash

For example:

127.0.0.1 name 6379 > hgetall he1) "sex" 2) "nan" 3) "name" 4) "wanger" 5) "age" 6) "18" gets all the fields hkeys key in the hash

For example:

127.0.0.1 name 6379 > hkeys he1) "sex" 2) "name" 3) "age" to determine whether there is a hexists key field in the hash field

For example:

127.0.0.1 hexists he name 6379 > hexists he sex (integer) 1 increments the value of the hash field by hincrby key field increment

For example:

127.0.0.1 hincrby asd asdf 6379 > hget asd asdf 2 (integer) 3127.0.0.1 hincrby asd asdf 6379 > hincrby asd asdf 2 (integer) 5127.0.0.1 hincrby asd asdf 6379 > hget asd asdf "5" gets all the values in the hash hvals key

For example:

127.0.0.1 wanger 6379 > hvals he1) "nan" 2) "wanger" 3) "18" Internal Encoding: ziplist (compressed list): when the number of elements of hash type is less than that of hash-max-ziplist-entries configuration (default 512) and all values are less than hash-max-ziplist-value configuration (default 64 bytes), Redis uses ziplist as the internal implementation of hash, and ziplist uses a more compact structure to achieve continuous storage of multiple elements. So it is better than hashtable in terms of memory savings. Hashtable (hash table): when the hash type does not meet the conditions of ziplist, Redis will use hashtable as the internal implementation of the hash, because the read and write efficiency of ziplist will decrease, while the read and write time complexity of hashtable is O (1).

For example:

127.0.0.1 hmset hash asd fcfg zdf ftyOK 6379 > hset ziplist hash 12335452335235fwgvsfwbhfbwhhfwuesrfhwueywhufgbrewfghusfhwueughsajkifo34ejigji (integer) 1127.0.0.1

A collection of unique and unordered string elements.

Add one or more members to the collection sadd key member1 member2

For example

127.0.0.1 smembers key 6379 > sadd set S1 S2 (integer) 0 gets all the values of the collection smembers key

For example:

127.0.0.1 6379 > smembers set1) "S2" 2) "S1" 3) "S3" deletes the element srem key member1 members2 of the collection

For example:

127.0.0.1 srem set 6379 > srem set S2 (integer) 1127.0.0.1 smembers set1) "S1" 2) "S3" gets the length scard key of the element

For example:

127.0.0.1 srandmember key 6379 > scard set (integer) 2 randomly gets the specified number of elements srandmember key [count]

For example:

127.0.0.1 sismember key member 6379 > srandmember set 11) "S1" determines whether the element is in the collection or not

For example:

127.0.0.1 sismember set 6379 > sismember set s3 (integer) 1 pops up a specified number of elements spop key [count] from the collection

For example:

127.0.0.1 spop set 6379 > smembers set1) "S5" 2) "S4" 3) "S1" 4) "S3" 127.0.0.1) 6379 > spop set "S4" 127.0.0.1 spop set 31) "S5" 2) "S1" 3) "S3" 127.0.0.16379 > sunion key1 key2 between sets of smembers set (empty list or set)

For example:

127.0.0.1 sadd set1 6379 > sadd set2 123 (integer) 3127.0.0.1 sadd set2 6379 > sadd set2 2345 (integer) 4127.0.0.1 sadd set2 6379 > sunion set1 set21) "1" 2) "2" 3) "3" 4) "4" 5) intersection between sets sinter key1 key2

For example:

127.0.0.1 sinter set1 set21 6379 > difference set operation sdiff key1 key2 between "2" 2) "3" sets

For example:

127.0.0.1Redis 6379 > sdiff set1 set21) "1" 127.0.0.1 intset > sdiff set2 set11) "4" 2) "5" Internal Encoding intset (set of integers): when all elements in the set are integers and the number of elements is less than the number of elements configured by Redis (default 512), Redis will choose intset as the internal implementation of the collection, thus reducing the use of memory. Hashtable (hash table): when the collection type does not meet the conditions of intset, Redis uses hashtable as the internal implementation of the collection.

For example:

127.0.0.1 sadd set3 S1 S2 S3 (integer) 3127.0.1 object encoding set3 "hashtable" 127.0.0.1 object encoding set3 6379 > sadd set4 123 (integer) 3127.0.0.1 sadd set4 6379 > object encoding set4 "intset" ordered set

Each string element is associated with a floating-point value called score. Elements are always sorted by their scores, so unlike Sets, a series of elements can be retrieved

Add element zadd key [NX | XX] [CH] [INCR] score1 member1 score2 member2

For example:

127.0.0.1 huazai 6379 > zadd score xx 80 wanger 80 huazai 95 dongdong + inf a (integer) 0127.0.1 huazai 6379 > zrange score 0-11) "huazai" 2) "wanger" 3) "dongdong" 4) "a" + inf and-inf denote positive infinity and negative infinity to obtain a member's score zscore key member, respectively.

For example:

127.0.0.1 zscore score dongdong 6379 > zrevrange key start end "95" ranks members, starting with 0 zrange key start end [withscores] # ascending order zrevrange key start end [withscores] # descending order

For example:

127.0.0.1 wanger 6379 > zadd score 95 huazai 90 wanger 85 dongdong + inf a (integer) 0127.0.0.1 dongdong > zrank score huazai (integer) 2127.0.1 > zrevrank score huazai (integer) 1127.0.1 > zrevrank score a (integer) 0127.0.1) WITHSCORES1) "dongdong" 2) "85" 3) "wanger" 4) "90" 5) "huazai" 6) "95" 7) "a" 8) "inf" gets the number of members zcard key

For example:

127.0.0.1 zrem key member1 member2 6379 > zcard score (integer) 4 Delete member zrem key member1 member2

For example:

127.0.0.1 zrange score 6379 > zrem score dongdong (integer) 1127.0.0.1 zrange score 0-11) "wanger" 2) "huazai" 3) "a" increases the member's score zincrby key increment member

For example:

127.0.0.1 wanger 6379 > zincrby score 5 wanger "95" get the member zrangebyscore key min max [withscores] [limit offset count] # Ascending zrevrangebyscore key max min [withscores] [limit offset count] # descending order

For example:

127.0.0.1dongdong 6379 > zrangebyscore score 8090 withscores1) "dongdong" 2) "85" 3) "wanger" 4) "90" 127.0.0.1 zrevrangebyscore score 9580 withscores1) "huazai" 2) "95" 3) "wanger" 4) "90" 5) "dongdong" 6) "85" get the number of members in the specified score range zcount key min max

For example:

127.0.0.1 zremrangebyscore key min max 6379 > zcount score 85 95 (integer) 3 Delete member zremrangebyscore key min max in specified score range

For example:

127.0.1 zinterstore destination numkeys key1 key2 6379 > zremrangebyscore score 8590 (integer) 2 intersection operation of ordered sets zinterstore destination numkeys key1 key2 [WEIGHTS weight] destination: the result of the intersection calculation is saved to this key. Numkeys: need to do intersection to calculate the number of keys. Key [key...]: keys that need to do intersection calculations. Weights weight [weight...]: the weight of each key. When calculating the intersection, each member in each key multiplies its own score by this weight, and the weight of each key defaults to 1. Aggregate sum | min | max: after calculating the intersection of members, the score can be summarized by sum (and), min (minimum) and max (maximum). The default value is sum.

The end result is the weight multiplied by the score, and then aggregated.

For example:

127.0.0.1 dongdong 6379 > zadd user 10 wanger 20 huazai 30 dongdong (integer) 3127.0.1 huazai 6379 > zadd user1 15 wanger 35 huazai (integer) 2127.0.0.1 aggregate min 6379 > zinterstore userset 2 user user1 (integer) 2127.0.1 zrange userset 0-1 withscores1) "wanger" 2) "25" 3) "huazai" 4) "55" 127.0.1 user user1 weights 1 0.5 aggregate min (integer) 2127.0 .0.1 wanger 6379 > zrange user2set 0-1 withscores1) "wanger" 2) "7.5" 3) "huazai" 4) Union calculation of "17.5" ordered sets zunionstore destination numkeys key [key...] [WEIGHTS weight]

For example:

127.0.0.1 dongdong 6379 > zadd user 10 wanger 20 huazai 30 dongdong (integer) 3127.0.1 huazai 6379 > zadd user1 15 wanger 35 huazai (integer) 2127.0.0.1 aggregate max 6379 > zunionstore user3set 2 user user1 weights 1 0.5 aggregate max (integer) 3127.0.1 aggregate max > zrange user3set 0-1 withscores1) "wanger" 2) "10" 3) "huazai" 4) "20" 5) "dongdong" 6) "30" internal coding ziplist (compression) List): when the elements of an ordered collection are smaller than the zset-max-ziplist-entries configuration (the default is 128) At the same time, when the value of each element is less than zset-max-ziplist-value (the default is 64 bytes), Redis will use ziplist as the internal coding implementation of ordered sets. Ziplist can effectively reduce the use of memory skiplist (jump table): when the conditions of ziplist are not met, ordered sets will use skiplist as the implementation of internal coding to solve the problem of reduced reading and writing efficiency caused by ziplist.

For example:

127.0.0.1zadd sortset2 6379 > zadd sortset1 10a 20b 30 c (integer) 3127.0.0.1 zadd sortset2 6379 > object encoding sortset1 "ziplist" 127.0.0.1 cddddddddddddddddddddddffffffffffffffffffffffffwfwfwggggggggggggggggggwg4yhhhhhhhhhhhhhhhh (integer) 3127.0.0.16379 > object encoding sortset2 "skiplist"

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