anggadarkprince / learn-redis

Learn Redis

REDIS

Run Redis With Docker

1. docker-compose -f docker-compose.yaml up -d
2. docker container exec -it redis /bin/sh
3. redis-cli -h localhost
4. ping will return PONG

Redis Command Operation

Select Database

select [index] by default 0-15 or 16 databases (based on default config)

Set Value

set [key] [value] set name "Angga Ari"

Get Value

get [key] get name

Check If Key Exist

exists [key] [key] ... exists name age

Delete Value

del [key] del name

Append Value

append [key] [value] (will append the string rather than replace) append name "ari wijaya" append not-found-key "hello world" (will create new key like set value)

Get Multiple Keys (Pattern)

keys [patern] keys na* keys * (get all keys)

Operation Range

getrange [key] [start] [end] setrange [key] [start] [value]

Get Multiple Value

mget [key] [key] ... mget name age

Set Multiple Value

mset [key1] [value1] [key2] [value2] mset address "Avenue Street" gender male

Expiration

setex [key] [seconds] [value] expire [key] [seconds] ttl [key] (result -1 meaning never expired)

Increment & Decrement

incr [key] (key should number, or if not set it will create new value from 1) decr [key] incrby [key] [total incr] decrby [key] [total decr]

Flush

flushdb (remove all keys from current database) flushall (remove all keys from all databases)

Redis Pipeline

cat sets.txt | redis-cli -h localhost --pipe (run command inside file into redis)

Transaction

multi mark the start of a transaction block set [key] [value] set operation del [key] del operation another command exec execute all commands issued after multi (will commit or fail if one or more command error) discard discard all commands issued after multi (cancel whatever commands after multi)

Monitor

monitor will activate state to capture all command

Server Information

info get information and statistics about server config [sub: get|set|resetstat|rewrite] get the value a configuration parameter slowlog return top entries from the slowing

Client Connection

client list get the list of client connections client id return client id for the current connection client kill ip:port kill the connection of a client

Redis Security

config bind 127.0.0.1 will setting redis to allowed access outside the host config protected-mode yes will allow connect from outside but only proceed request (command) from localhost

Redis Authentication

config user default on +@connection create default user to making connection config user angga on +@all -DEBUG ~* >anggaari use new user to access all commands auth [username] [password] login with user in redis-cli

Redis Authorization

acl cat show group category of keys config user angga on +@all -@set ~* >anggaari the ~ give key access, the +@all give command access, -@set prevent set command

Persistence

redis will periodically store data from memory to persistence storage like harddisk config save [seconds] [changes] save synchronously save the dataset to disk bgsave asynchronously save the dataset to disk

Eviction

when memory full, by default noeviction will reject new data. redis has strategy that can delete old data and receive new data

eviction has configuration to set max memory and policy to manage the data, config maxmemory need to be set

config eviction policy: LRU means Least Recently Used LFU means Least Frequently Used

volatile-lru -> Evict using approximated LRU, only keys with an expire set. allkeys-lru -> Evict any key using approximated LRU. volatile-lfu -> Evict using approximated LFU, only keys with an expire set. allkeys-lfu -> Evict any key using approximated LFU. volatile-random -> Remove a random key having an expire set. allkeys-random -> Remove a random key, any key. volatile-ttl -> Remove the key with the nearest expire time (minor TTL) noeviction -> Don't evict anything, just return an error on write operations.