Redis Core configuration and advanced data types

Make changes in the configuration file

1、 Basic server settings

Server settings

1. Set the server to run as a daemons

   daemonize yes|no
   

2. Bind host address

   bind 127.0.0.1
   

3. Set the server port number

   port 6379
   

4. Set the number of databases

   databases 16
   

Log configuration

Be careful ： The log level development period is set to verbose that will do , In the production environment, the configuration is notice, Simplify log output , Reduce write log IO The frequency of

1. Set up the server to specify the logging level

   loglevel debug|verbose|notice|warning
   

2. Log file name

   logfile  Port number .log
   

Client configuration

1. Sets the maximum number of client connections at one time , Default limit . When the client connection reaches the upper limit ,Redis Will close the new connection

   maxclients 0
   

2. The maximum waiting time of idle client , Close the connection when the maximum value is reached . To turn off the function , Set to 0

   timeout 300
   

Multi server quick configuration

1. Import and load the specified profile information , Used to quickly create redis There are more public facilities redis Instance configuration file , Easy to maintain

   include /path/server- Port number .conf
   

2、 Advanced data types

1、Bitmaps

Bitmaps Type of basic operation

Get specified key Corresponding to... On the offset bit value

getbit key offset

Set the specified key Corresponding to... On the offset bit value ,value Can only be 1 or 0

setbit key offset value

Bitmaps Type extension operation

Business scenario

Movie website

1. Count whether a movie is on demand every day
2. Count how many movies are on demand every day
3. Statistics weekly / month / How many films were on demand in
4. Count which movies are not on demand in the year

Business analysis

Bitmaps Type extension operation

1. Specify key Hand in by position 、 and 、 Not 、 Exclusive or operation , And save the result to destKey in

   bitop op destKey key1 [key2...]
   # and： hand over 
   # or： and 
   # not： Not 
   # xor： Exclusive or 
   

2. Specify Statistics key in 1 The number of

   bitcount key [start end]
   

redis Apply to information status system

2、HyperLogLog

Statistical independence UV

1. The original plan ：set Store each user's id（ character string ）
2. The improved scheme ：Bitmaps Store each user state （bit）
3. A new solution ：Hyperloglog

base

1. Cardinality is the data set to After heavy Element number
2. HyperLogLog It is used for cardinality Statistics , Use of the LogLog The algorithm of

HyperLogLog Type of basic operation

#  Add data 
pfadd key element [element ...]
#  statistics 
pfcount key [key ...]
#  Merge data 
pfmerge destkey sourcekey [sourcekey...]

redis Applied to independent information statistics

Related instructions

1. Used for cardinal Statistics , It's not a collection , Don't save data , Just record the quantity, not the specific data
2. The core is Cardinality estimation algorithm , There is a certain error in the final value
3. Error range ： The result of cardinality estimation is a function with 0.81% Approximate value of standard error
4. Minimal space consumption , Every hyperloglog key Occupied 12K Memory used to mark cardinality
5. pfadd Command is not a one-time assignment 12K Memory usage , As the base increases, the memory increases
6. Pfmerge The storage space occupied after command merging is 12K, Regardless of the amount of data before merging

3、GEO

redis Applied to geographic location calculation

GEO Type of basic operation

#  Add coordinate points 
geoadd key longitude latitude member [longitude latitude member ...]
#  Get coordinate points 
geopos key member [member ...]
#  Calculate the distance between coordinate points 
geodist key member1 member2 [unit]

GEO Type of basic operation 2

#  Add coordinate points 
georadius key longitude latitude radius m|km|ft|mi [withcoord] [withdist] [withhash] [count count]
#  Get coordinate points 
georadiusbymember key member radius m|km|ft|mi [withcoord] [withdist] [withhash] [count count]
#  Calculate latitude and longitude 
geohash key member [member ...]

Example of setting range

Get the information within the distance