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Redis basic knowledge, let's review it

2022-07-28 08:41:00 【Chon.Wang】

# Preface

Redis yes key-value The storage system , It's cross platform Non relational database . Point me into the Redis Official website .

Redis Support data persistence , The data in memory can be saved periodically in disk files , Recoverable for reuse .
Redis Support String 、list、set、Zset、hash And other data structures
Redis Can be used to do Cache of data 、 Ranking of data 、 Message queue Such as the scene

I don't say much nonsense , The basics begin .

One 、 Installation and configuration

Here are just a few Linux Source code installation .

1.1 Linux install Redis

#  install 

#  download  redis  The latest stable source file 
wget https://download.redis.io/redis-stable.tar.gz

#  decompression 
tar -zxvf redis-stable.tar.gz

#  Entry directory 
cd redis-stable

#  compiling  make
make

#  Execution and installation 
make install PREFIX=/usr/local/redis

#  Check whether the installation is successful , bin  If the directory exists, the installation succeeds 
cd /usr/local/redis

1.2 Redis Server startup

1.2.1 preparation

# 1.  Enter the unzipped directory just now ,  Copy  redis.conf  File to the installation directory  bin  Directory 
cp /root/redis-stable/redis.conf /usr/local/redis/bin

# 2.  modify  redis.conf
vim redis.conf

# 3.  Input  /  Get into  vim  Last row mode ,  Search for  daemonize,  Turn daemon mode on 

# 4.  take  daemonize  Change it to  yes

# 5. vim  Save and exit

1.2.2 start-up redis Server side

# 1.  Get into  /usr/local/redis/bin
cd /usr/local/redis/bin

# 2.  With  redis.conf  File is configuration file ,  start-up  redis
./redis-server redis.conf

# 3.  Check to see if startup succeeded 
ps -ef | grep redis

1.2.3 close redis Server side

#  Kill process 
kill -9 redis The process of ID

#  close  redis  service 
./redis-cli shutdown

1.3 Redis The configuration file

#  Just list some common configurations 

vim /usr/local/redis/bin/redis.conf

#  The following is the configuration content 

daemonize no|yes #  Whether to open the daemon to run 

pidfile /var/run/redis_6379.pid #  When the daemon is turned on ,  By default  pid  write in  /var/run/redis_6379.pid  in 

port 6379 # redis  Default listening port 

bind 127.0.0.1 #  The default bound host IP

timeout 300 #  The connection will be closed after the client is idle for the longest time ,  Set to  0  It means that the function is turned off 

databases 16 #  Default  16  Number of databases ,  The default is  0  database 

maxclients 128 #  Set the maximum number of client connections at the same time ,  Default limit

Two 、 Redis data type

Redis There are five types of data : character string (strings)、 Hash (hashes)、 list (lists)、 aggregate (sets)、 Ordered set (sorted sets).

Check me out. - Redis Official order book

#  Start again  redis ,  Entry directory 
cd /usr/local/redis/bin

#  start-up  redis  Server side 
./redis-server redis.conf

#  start-up  redis  client 
./redis-cli

#  The following command needs to be in  Redis  Client operation

2.1 character string (strings)

The string is redis Basic 、 Common types , One key Corresponding to one value
The maximum value cannot be greater than 512 MB
It can be saved character string 、json、 binary data 、 picture 、 Serialize values, etc
Application scenarios ： Cache basic data 、 Counter, etc
Common commands : exists、set、get、mset、mget、del、append、decr、incr、decrby、incrby、incrbyfloat、strlen、、、、、、、``、

# redis-cli  Client command line 

# 1.  Whether there is a key name : exists  Key name 
	exists name # 0

# 2.  Set individual : set  Key name   value 
	set name Chon

# 3.  Get a single : get  Key name 
	get name
	
# 4.  Set up multiple : mset  Key name 1  value 1  Key name 2  value  [ Key name n  value n]
	mset domain bqhub.com author Chon
	
# 5.  Get multiple : mget  Key name 1  Key name 2 [ Key name n]
	mget domain author

# 6.  Delete : del  Key name 
	del name

# 7.  Additional : append  Key name   value 
    set name Chon #  So let's set up a 
    append name Wang #  Additional 
    get name #  Output : ChonWang
    
# 8.  Minus one ( Integers ): decr  Key name 
	set age 18 #  Set a value to a number 
	decr age #  Output minus  1  After the value of  17
	
# 9.  Add one ( Integers ): incr  Key name 
	set height 180 #  Set a value to a number 
	incr height #  Output plus  1  After the value of  181
	
# 10.  Subtraction ( Integers ): decrby  Key name   step 
	set age 18 #  Set a value to a number 
	decrby age 10 #  Output minus  10  After the value of  8
	
# 11.  Add ( Integers ): incrby  Key name   step 
	set height 180 #  Set a value to a number 
	incrby height 10 #  Output plus  10  After the value of  190
	
# 12.  Add ( Floating point numbers ): incrbyfloat  Key name   step 
	set weight 65.2  #  Set a value to a number 
	incrbyfloat weight 1.3 #  Output plus  1.3  After the value of  66.5
	
# 13.  Get value length : strlen  Key name 
	strlen domain

2.2 Hash (hashes)

A hash is a collection of key value pairs （key=>value）
Often used to save object
Application scenarios ：
Common commands hset、hget、hmset、hmget、hdel、hgetall、hkeys、hvals、hlen、hstrlen、hexists

# redis-cli  Client command line 

# 1.  Single data operation 
	#  Set individual : hset  Key name   Field name   value 
	hset bqhub domain bqhub.com
	
	#  Get a single : hget  Key name   Field name 
	hget bqhub domain

# 2.  Multiple data operations 
	#  Set up multiple : hmset  Key name   Field name 1  value 1  Field name 2  value 2 [ Field name n  value n]
	hmset bqhub domain bqhub.com author Chon

	#  Get multiple : hmget  Key value   Field name 1 [ Field name n]
	#  Return array format display 
	hmget bqhub domain author

	#  Removing a single : hdel  Key name   Field name  [ Field name n  value n]
	hdel bqhub domain author
	
# 3.  Get all the data ( Key name and value ): hgetall  Key name 
	hgetall bqhub
	
# 4.  Get all field names : hkeys  Key name 
	hkeys bqhub
	
# 5.  Get all values : hvals  Key name 
	hvals bqhub
	
# 6.  Get the number of fields : hlen  Key name 
	hlen bqhub
	
# 7.  Get the length of the field value : hstrlen  Key name   Field name 
	hstrlen bqhub domain
	
# 8.  Whether this field exists ,  If the key name does not exist ,  Also returned  0
	hexists bqhub domain # 1
	hexists bqhub name # 0
	hexists aaaaa sex # 0

2.3 list (lists)

Lists are linked results , Sort in the order of insertion , Elements can be inserted or popped from both ends .
Application scenarios ： example : Left in right out message queue
Common commands ：lpush、lpushx、rpush、rpushx、linsert、lrange、lindex、lpop、blpop、rpop、brpop、lrem、ltrim、lset、llen

# 1.  Insert... On the left ( If the list does not exist, create ): lpush  List name  value1 [value...]
	lpush testLpush v1 v2 v3

# 2.  Insert... On the left ( The list doesn't exist ,  No operation ): lpushx  List name  value1 [value...]
	lpushx testLpush v4 #  success 
	lpushx aaa a1 #  Failure ,  because  aaa list  non-existent 

# 3.  Insert... On the right ( If the list does not exist, create ): rpush  List name  value1 [value...]
	rpush testRpush v1 v2 v3

# 4.  Insert... On the right ( The list doesn't exist ,  No operation ): rpushx  List name  value1 [value...]
	rpushx testRpush v4 #  success 
	rpushx bbb b1 #  Failure ,  because  bbb list  non-existent 

# 5.  Insert a new element before or after the element : linsert  List name  before|after  Existing element values   New element value 
	linsert testLpush before v2 v22
	linsert testLpush after v3 v33

# 6.  Query list : lrange  List name   Start index   End index 
	# 0 1  It's No   One   Two   Elements , -1 -2  Is the penultimate   Two elements ,  And so on 
	lrange testLpush 0 -1
	
# 7.  Query element : Get elements from index : lindex  List name   Indexes 
	lindex testLpush 1

# 8.  The first element on the left pops up : lpop  List name 
	lpop testLpush

# 9.  The first element on the left pops up : blpop  List name   Timeout seconds 
	#  If the list is empty ,  Then wait for the timeout to stop or the element is found within the timeout and pop up 
	blpop testLpush 3

# 10.  The first element on the right pops up : rpop  List name 
	rpop testRpush

# 11.  The first element on the right pops up : brpop  List name   Timeout seconds 
	#  If the list is empty ,  Then wait for the timeout to stop or the element is found within the timeout and pop up 
	brpop testRpush 3
	
# 12.  Delete a certain number of elements : lrem  List name   Number   Elements 
	# > 0  Left to right 
	# < 0  From right to left 
	# = 0  Delete all 
	lrem testLpush 2 'v3'
	
# 13.  Keep elements in a certain range : ltrim  List name   Start index   end fqxh
	ltrim testLpush 1 4 #  Keep only the index  1  To  4  The elements of ,  Delete all others 

# 14.  Replace the value of an index : lset  List name   Indexes   The new value 
	lset testLpush 1 'v11'
	
# 15.  Get the length of the list : llen  List name 
	llen testLpush

2.4 unordered set (sets)

A collection of string elements
Duplicate elements are not allowed
unordered set , No subscript
Application scenarios ： Tags contain articles 、 Aggregation of fans concerned by users
Common commands ： sadd、scard、sdiff、sdiffstore、sinter、sinterstore、sunion、sunionstore、sismember、smismember、smembers、srandmember、smove、spop、srem

# 1.  Add elements... To the collection : sadd  Collection name  value1 [value...]
	sadd myset 1 2 3 4 5 6
	
# 2.  Get the total number of collection elements : scard  Collection name 
	scard myset

# 3.  Difference set : sdiff  Gather one   Set two  [ aggregate n]
	#  Only get the difference set between the first set and subsequent sets 
	sadd setnum 1 2 3 11 12 13
	sdiff myset setnum #  return  4 5 6 
	
# 4.  Save difference : sdiffstore  New collection name   Compare sets 1  More collective 2 [ Compare sets n]
	sdiffstore diffset myset setnum #  Save the difference set to  diffset  In new collection 
	
# 5.  intersection : sinter  Gather one   Set two  [ aggregate n]
	#  Returns the intersection of all sets 
	sinter myset setnum #  return  1 2 3
	
# 6.  Intersection save : sinterstore  New collection name   Compare sets 1  More collective 2 [ Compare sets n]
	sinterstore interset myset setnum #  Save the intersection to  interset  In new collection 
	
# 7.  Combine : sunion  Gather one   Set two  [ aggregate n]
	#  Returns the union of all sets 
	sunion myset setnum
	
# 8.  Union save : sunionstore  New collection name   Compare sets 1  More collective 2 [ Compare sets n]
	sunionstore unionset myset setnum #  Save union to  unionset  In new collection 
	
# 9.  Whether elements exist : sismember  Collection name  value
	sismember myset 1 # 1
	sismember myset 100 # 0
	
# 10.  Whether multiple elements exist : smismember  Collection name  value1 value2 [value...]
	smismember myset 1 2 100 200
	
# 11.  Get all the elements : smembers  Collection name 
	smembers myset
	
# 12.  Random return  n  Elements : srandmember  Collection name   Number n
	srandmember myset 2 #  Returns two elements at random 
	
# 13.  Move element to new collection : smove  The original assembly   New collection  value
	smove myset setnum 5
	
# 14.  Remove randomly  n  Elements : spop  Collection name   Number n
	spop myset 2 #  Remove randomly  2  Elements ,  And return these two elements 
	
# 15.  Remove an element : srem  Collection name  value
	srem myset 1

2.5 Ordered set (Sorted Set)

A collection of string elements
Duplicate elements are not allowed
Orderly sorting , The default order is from small to large
Set a score for each element , The scores can be the same , Sort by score
Application scenarios ： Ranking list of various rules
Common commands ：zadd、zrandmember、zrange、zrangestore、zrangebyscore、zrank、zscore、zmscore、zcard、zcount、zrevrange、zrevrangebyscore、zrevrank、zmpop、zpopmax、zpopmin、zrem、zremrangebyrank、zremrangebyscore、zdiff、zdiffstore、zunion、zunionstore、zinter、zinterstore、zintercard、zincrby

# 1.  Add or update elements : zadd  Collection name  [ Options ]  fraction 1  value 1  fraction 2  value 2 [...]
	#  Common options 
	# xx :  Only update without adding 
	# nx :  Only add without updating 
	# lt :  New score   lower than   The current score is only updated , Reinsert the correct sort position after update 
	# gt :  New score   Greater than   The current score is only updated , Reinsert the correct sort position after update 
	zadd myzset 98 yuwen 112 shuxue 102 yingyu 91 wuli 98 zhengzhi

# 2.  Get elements  -  Randomly returned  n  individual : zrandmember  Collection name   Number n [withscores]
	zrandmember myzset 2 withscores #  Returns two elements at random ,  And show the score 
	
# 3.  Get elements  -  According to the index range : zrange  Collection name   Start index   End index  [withscores]
	# 0 1  It's No   One   Two   Elements , -1 -2  Is the penultimate   Two elements ,  And so on 
	zrange myzset 0 -1 withscores
	
# 4.  Get elements  -  According to the index range  -  Save to new collection : zrangestore  New collection name   Original set name   Start index   End index 
	# 0 1  It's No   One   Two   Elements , -1 -2  Is the penultimate   Two elements ,  And so on 
	zrangestore new_myzset myzset 2 -1
	
# 5.  Get elements  -  According to the score range : zrangebyscore  Collection name   Minimum score   Maximum score  [withscores]
	zrangebyscore myzset 95 105 withscores
	
# 6.  Get index subscript  -  According to element value : zrank  Collection name  value
	zrank myzset shuxue
	
# 7.  Get a single score  -  According to element value : zscore  Collection name  value
	zscore myzset shuxue

# 8.  Get multiple scores  -  According to element value : zmscore  Collection name  value1 value2 [value...]
	zmscore myzset shuxue yingyu
	
# 9.  Get the total number of elements : zcard  Collection name 
	zcard myzset
	
# 10.  Get the number of elements  -  According to the score range : zcount  Collection name   Minimum score   Maximum score 
	zcount myzset 95 105

# 11.  Get elements  -  According to the index range  -  Sort from large to small : zrevrange  Collection name   Start index   End index  [withscores]
	zrevrange myzset 0 2 withscores
	
# 12.  Get elements  -  According to the score range  -  Sort from large to small : zrevrangebyscore  Collection name   Maximum score   Minimum score  [withscores]
	zrevrangebyscore myzset 105 60 withscores
	
# 13.  Get index subscript  -  According to element value  -  Sort from large to small : zrevrank  Collection name  value
	zrevrank myzset shuxue
	
# 14.  Remove the largest or smallest element : zmpop  Number of sets   aggregate 1  aggregate 2 [ aggregate n] min|max [count  Number ]
	zmpop 1 myzset max 2 #  Pop up the two largest elements 
	
# 15.  Remove the largest element : zpopmax  Collection name 
	zpopmax myzset

# 16.  Remove the smallest element : zpopmin  Collection name 
	zpopmin myzset
	
# 17.  Remove elements  -  According to the element : zrem  Collection name  value
	zrem myzset shuxue
	
# 18.  Remove elements  -  According to the index range : zremrangebyrank  Collection name   Start index   End index 
	zremrangebyrank myzset 0 2
	
# 19.  Remove elements  -  According to the score interval : zremrangebyscore  Collection name   Minimum score   Maximum score 
	zremrangebyscore myzset 0 60
	
# 20.  Difference set : zdiff  Number of sets   aggregate 1 [ aggregate n] [withscores]
	#  Only get the difference set between the first set and subsequent sets 
	zdiff 2 myzset myzset1
	
# 21.  Save difference : zdiffstore  New collection name   Number of sets   aggregate 1  aggregate 2 [ aggregate n] [withscores]
	zdiffstore diffzset 2 myzset myzset1 #  Save the difference set to  diffzset  In new collection 
	
# 22.  Combine : zunion  Number of sets   aggregate 1  aggregate 2 [ aggregate n] [withscores]
	#  Returns the union of all sets 
	zunion 2 myzset myzset1
	
# 23.  Union save : zunionstore  New collection name   Number of sets   aggregate 1  aggregate 2 [ aggregate n]
	zunionstore unionzset myzset myzset1 #  Save union to  unionzset  In new collection 

# 24.  intersection : zinter  Number of sets   aggregate 1  aggregate 2 [ aggregate n] [withscores]
	zinter 2 myzset myzset1
	
# 25.  Intersection save : zinterstore  New collection name   Number of sets   aggregate 1  aggregate 2 [ aggregate n]
	zinterstore interzset 2 myzset myzset1 #  Save the difference set to  interzset  In new collection 

# 26.  The number of intersections : zintercard  Number of sets   aggregate 1  aggregate 2 [ aggregate n]
	zintercard 2 myzset myzset1

# 27.  Add ( Integers ): zincrby  Collection name   Points to be added   Element value 
	zadd my 180 height #  Set a value to a number 
	zincrby my 2 height #  Output plus  2  After the value of  182

3、 ... and 、Redis Business

Redis Multiple commands can be executed at one time .
Redis Bulk operation is sending exec The command is put into the queue cache before , Waiting for execution .
Because it has been put into the queue cache , Therefore, operations outside the transaction will not change the data inside the transaction .
received exec Execute the operation after the command , If the command format is incorrect , Do not perform , If there is no mistake , execute , Even if one command fails , The rest of the commands are still executed .

Redis There are three stages from the beginning to the end of a transaction ： Start business 、 Order to join the team 、 Perform transactions

3.1 Redis Transaction related orders

# 1.  Monitor one or more  key, If before the transaction is executed , relevant  key  Altered by other orders , Then the transaction will be interrupted and not executed 
	watch key1 key2 [key...]
	
# 2.  Mark the beginning of the transaction block 
	multi

# 3.  Execute commands within all transaction blocks 
	exec

# 4.  Cancel the business , Give up executing all commands in the current transaction block 
	discard
	
# 5.  Cancel  watch  Command to all  key  Surveillance 
	unwatch

3.2 Case affairs

#  Case study ,  In business ,  The successful execution of the statement returns  QUEUED

set coll_num 10

watch coll_num #  monitor   Collect the number 

multi #  Open transaction 

incr coll_num #  Self increase 1, 

exec

unwatch

Four 、 Commonly used Redis Server command

# 1.  obtain  Redis  All statistics 
	info

# 2.  Set the current connection name 
	client setname testClient
	
# 3.  Get the current connection name 
	client getname
	
# 4.  Clear the current connection name 
	client setname ""
	
# 5.  Get the current server time 
	time
	
# 6.  Delete the  key
	flushall
	
# 7.  Delete the  key
	flushdb
	
# 8.  Real time printing  Redis  Commands received by the server 
	monitor
	
# 9.  Save data to hard disk 
	save

# 10.  See if the service is running 
	ping
	
# 11.  Switch to the specified database . I mentioned before ,  Default  16  Number of databases ,  The default is  0  database : select index
	select 3 #  Switch to  3  database 
	
# 12.  Close the current connection 
	quit