redis

• 应用场景
• 快速开始
• 数据类型
• 配置文件
• 主从
• 分片

是一个开源的C语言编写的k-v数据库

应用场景

1. 数据缓存

2. session 共享

3. 排行榜/计数器

   nginx+lua+redis计数自动封ip

4. 消息队列

   kafka rabbitMQ

快速开始

root@debian:~# redis-cli
127.0.0.1:6379> SET name wanndao
OK
127.0.0.1:6379> SET age 30
OK
127.0.0.1:6379> KEYS *
1) "name"
2) "age"
127.0.0.1:6379> KEYS *

数据类型

1. string

   set

   SET name wangendao
   # 30s 后删除
   SET name wangendao ex 30 
   get name
   

   append

   127.0.0.1:6379> APPEND name 123
   (integer) 12
   127.0.0.1:6379> get name
   "wangendao123"
   

   mset

   127.0.0.1:6379> mset name wangendao age 30
   OK
   127.0.0.1:6379> mget name age
   1) "wangendao"
   2) "30"
   

   strlen 字符串长度

   127.0.0.1:6379> STRLEN name
   (integer) 9
   127.0.0.1:6379> STRLEN age
   (integer) 2
   

   incr 整数自增

   127.0.0.1:6379> INCR age
   (integer) 31
   

   decr 整数自减

   127.0.0.1:6379> DECR age
   (integer) 30
   

   incrby 指定自增步长

   127.0.0.1:6379> INCRBY age 100
   (integer) 130
   

   decrby

   127.0.0.1:6379> DECRBY age 100
   (integer) 30
   

2. list

   LPUSH 和 RPUSH

   127.0.0.1:6379> LPUSH user user01 user02 user03
   (integer) 3
   

   llen

   127.0.0.1:6379> LLEN user
   (integer) 3
   

   LRANGE

   127.0.0.1:6379> LRANGE user 0 3
   1) "user03"
   2) "user02"
   3) "user01"
   

   LPOP 和RPOP

   127.0.0.1:6379> LPOP user
   "user03"
   127.0.0.1:6379> RPOP user
   "user01"
   

   lrem

   # 删除列表user中的2个 user02 元素 
   192.168.122.1:6379> LREM user 2 user02
   (integer) 2
   
   # 删除列表user中所有的 user01
   192.168.122.1:6379> LREM user 0 user01
   (integer) 2
   
   # 删除列表user中 最右侧的user04
   192.168.122.1:6379> LREM user -1 user04
   (integer) 1
   

   lset

   # 修改0号索引位置的值
   192.168.122.1:6379> LSET user 0 wangendao
   OK
   192.168.122.1:6379> LRANGE user 0 10
   1) "wangendao"
   2) "user03"
   

   lindex

   192.168.122.1:6379> LINDEX user 0
   "wangendao"
   192.168.122.1:6379> LINDEX user 1
   "user03"
   

3. set

4. zset

5. hash

   hset

   127.0.0.1:6379> hset user:1 name wangendao
   127.0.0.1:6379> hset user:1 age 30
   127.0.0.1:6379> hset user:1 mail XXXX.qq.com
   

   hget

   127.0.0.1:6379> hget user:1 name
   "wangendao"
   127.0.0.1:6379> hget user:1 age
   "30"
   127.0.0.1:6379> hget user:1 mail
   "XXXX.qq.com"
   127.0.0.1:6379
   

   hgetall

   127.0.0.1:6379> HGETALL user:1
   1) "name"
   2) "wangendao"
   3) "age"
   4) "30"
   5) "mail"
   6) "XXXX.qq.com"
   

   hmset

   127.0.0.1:6379> hmset user:1 name wangendao age 30 mail xxx.qq.com
   OK
   127.0.0.1:6379> HMGET user:1 name age mail
   1) "wangendao"
   2) "30"
   3) "xxx.qq.com"
   

   HEXISTS

   127.0.0.1:6379> EXISTS user:1
   (integer) 1
   127.0.0.1:6379> HEXISTS user:1 name
   (integer) 1
   127.0.0.1:6379> HEXISTS user:1 name1
   (integer) 0
   

配置文件

如果通过yum/apt安装配置文件在/etc/redis/redis.conf

bind 0.0.0.0 ::
port 6379

##################
# rdb
dir /var/lib/redis
# /var/lib/redis/dump.rdb
dbfilename dump.rdb
# rdb 压缩
rdbcompression yes
##################
#
pidfile /var/run/redis/redis-server.pid
loglevel notice
logfile /var/log/redis/redis-server.log
# 启用安全机制
protected-mode yes
requirepass root
# 密码是root
#root@debian:~# redis-cli
#127.0.0.1:6379> AUTH root
#OK
#127.0.0.1:6379>

##################
appendfilename "appendonly.aof"
# no 按照文件系统的刷新机制
# always每次变更刷新到磁盘
# everysec 每秒刷新一次到磁盘
appendfsync everysec

通过config get * 查看当前配置

127.0.0.1:6379> CONFIG GET *

动态设置系统参数

127.0.0.1:6379> CONFIG SET loglevel debug
OK

tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize yes
supervised no


databases 16
always-show-logo yes

stop-writes-on-bgsave-error yes

rdbchecksum yes

rdb-del-sync-files no

replica-serve-stale-data yes
replica-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-diskless-load disabled
repl-disable-tcp-nodelay no
replica-priority 100
acllog-max-len 128
lazyfree-lazy-eviction no
lazyfree-lazy-expire no
lazyfree-lazy-server-del no
replica-lazy-flush no
lazyfree-lazy-user-del no
oom-score-adj no
oom-score-adj-values 0 200 800
appendonly no

no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb
aof-load-truncated yes
rdb-save-incremental-fsync yes           
jemalloc-bg-thread yes

主从

RDB (point-in-time snapshot) 定期生成快照
AOF 记录数据库的修改操作，当数据重启时从新执行文件的操作记录
可以同时使用RDB和AOF ，也可关闭持久化

# 900s 内有1次改动操作，就执行 RDB快照
save 900 1
 300s 内有10次改动操作，就执行 RDB快照
save 300 10
 60s 内有10000次改动操作，就执行 RDB快照
save 60 10000

########
appendfsync everysec 每秒操作同步到磁盘
appendfsync no 使用linux 同步 默认30s
appendfsync always 每次操作同步到磁盘

分片

参考

文档1

文档2