Redis雜記
阿新 • • 發佈:2018-05-07
Redis 基礎命令 主從 哨兵一、Redis基礎
1、安裝啟動Redis
1.1 去pkgs.org下載rpm包
[root@node1 ~]# wget http://www6.atomicorp.com/channels/atomic/centos/6/i386/RPMS/redis-3.0.7-4.el6.art.i686.rpm
1.2 yum本地安裝
[root@node1 ~]# yum localinstall redis-3.0.7-4.el6.art.i686.rpm 查看redis安裝生成的文件: [root@node1 ~]# rpm -ql redis 備份原始配置: [root@node1 ~]# cp -p /etc/redis.conf{,.orgi}
1.3 配置
[root@node1 ~]# vim /etc/redis.conf #監聽多個地址: bind 127.0.0.1 10.201.106.21 啟動: [root@node1 ~]# service redis start Starting redis-server: [ OK ] [root@node1 ~]# ss -tnlp | grep redis LISTEN 0 128 10.201.106.21:6379 *:* users:(("redis-server",16155,5)) LISTEN 0 128 127.0.0.1:6379 *:* users:(("redis-server",16155,4))
2、Redis使用
2.1 連接
[root@node1 ~]# redis-cli 127.0.0.1:6379> 獲取幫助: 127.0.0.1:6379> help 查看支持的字符: 127.0.0.1:6379> help @STRING 查看單個命令用法: 127.0.0.1:6379> HELP APPEND APPEND key value summary: Append a value to a key since: 2.0.0 group: string TAB鍵可以補全命令 127.0.0.1:6379> HELP 按tab 命令是分組的: 127.0.0.1:6379> help @server 列出連接的客戶端: 127.0.0.1:6379> CLIENT LIST
2.1.1 雜項
打開1號數據庫:
127.0.0.1:6379> SELECT 1
OK
127.0.0.1:6379[1]>
默認是0號數據庫:
127.0.0.1:6379[4]> SELECT 0
OK
127.0.0.1:6379>
2.2 數據類型常用命令
2.2.1 String
查看幫助:
127.0.0.1:6379> help @string
設置disto字串的值為fedora
127.0.0.1:6379> SET disto fedora
OK
獲取disto的值
127.0.0.1:6379> GET disto
"fedora"
在同一個名稱空間,對同一個鍵的二次定義,是修改其值:
127.0.0.1:6379> SET disto centos
OK
127.0.0.1:6379> GET disto
"centos"
附加延長字串:
127.0.0.1:6379> append disto slackware
(integer) 15
127.0.0.1:6379> GET disto
"centosslackware"
獲取字串長度:
127.0.0.1:6379> STRLEN disto
(integer) 15
NX:鍵不存在才設定
可以通過SETNX判斷鍵是否存在,不存在才創建,避免覆蓋之前的:
127.0.0.1:6379> SET disto gentoo NX
(nil) #提示操作未能執行
還是原來的值
127.0.0.1:6379> GET disto
"centosslackware"
XX:鍵存在才設定:
127.0.0.1:6379> SET foo bar XX
(nil)
設置count鍵值為0,通過INCR不斷加1
127.0.0.1:6379> SET count 0
OK
127.0.0.1:6379> INCR count
(integer) 1
127.0.0.1:6379> INCR count
(integer) 2
127.0.0.1:6379> INCR count
(integer) 3
127.0.0.1:6379> INCR count
(integer) 4
127.0.0.1:6379> GET count
"4"
減1:
127.0.0.1:6379> DECR count
(integer) 3
127.0.0.1:6379> DECR count
(integer) 2
127.0.0.1:6379> GET count
"2"
127.0.0.1:6379> DECR count
(integer) 1
127.0.0.1:6379> DECR count
(integer) 0
127.0.0.1:6379> DECR count
(integer) -1
127.0.0.1:6379> GET count
"-1"
無法遞增字符內容:
127.0.0.1:6379> set foo bar
OK
127.0.0.1:6379> incr foo
(error) ERR value is not an integer or out of range
2.2.2 List[字串容器]
查看幫助:
127.0.0.1:6379> help @list
定義一個列表:
127.0.0.1:6379> LPUSH list1 mon
(integer) 1
獲取第一個元素:
127.0.0.1:6379> lindex list1 0
"mon"
從左側賦值:
127.0.0.1:6379> LPUSH list1 sun
(integer) 2
127.0.0.1:6379> lindex list1 0
"sun"
127.0.0.1:6379> lindex list1 1
"mon"
從右側賦值:
127.0.0.1:6379> RPUSH list1 tue
(integer) 3
127.0.0.1:6379> LINDEX list1 2
"tue"
修改值:
127.0.0.1:6379> LSET list1 1 fri
OK
127.0.0.1:6379> LINDEX list1 1
"fri"
從右側彈出值(刪除):
127.0.0.1:6379> RPOP list1
"tue"
127.0.0.1:6379> RPOP list1
"fri"
127.0.0.1:6379> RPOP list1
"sun"
127.0.0.1:6379> RPOP list1
(nil) #沒有值了,無法執行
2.2.3 Sets(集合)
查看集合命令幫助:
127.0.0.1:6379> HELP @SET
創建一個新的集合:
127.0.0.1:6379> SADD w1 mon tue wed thu fri sat sun
(integer) 7
創建第二個集合:
127.0.0.1:6379> SADD w2 tue thu day
(integer) 3
求兩個集的交集(列出兩個集合,同時擁有的值):
127.0.0.1:6379> SINTER w1 w2
1) "thu"
2) "tue"
求並集(大家都有的只留一份):
127.0.0.1:6379> SUNION w1 w2
1) "mon"
2) "tue"
3) "wed"
4) "fri"
5) "sat"
6) "sun"
7) "thu"
8) "day"
彈出元素(隨機,無法控制):
127.0.0.1:6379> SPOP w1
"fri"
127.0.0.1:6379> SPOP w1
"sun"
判斷元素是否在集合裏面
127.0.0.1:6379> SISMEMBER w1 mon
(integer) 1
127.0.0.1:6379> SISMEMBER w1 sun
(integer) 0 #0表示不是
2.2.4 Sorted Sets(有序集合)
score=內建索引號碼,內置排序號碼。跟普通位置索引是兩回事。但是score大小決定你的索引位置
查看幫助:
127.0.0.1:6379> help @sorted_set
定義有序集合:
127.0.0.1:6379> ZADD weekday1 1 mon 2 tue 3 wed
(integer) 3
查看集合的元素個數:
127.0.0.1:6379> ZCARD weekday1
(integer) 3
查看元素對應的索引號:
127.0.0.1:6379> ZRANK weekday1 tue
(integer) 1
127.0.0.1:6379> ZRANK weekday1 wed
(integer) 2
根據元素獲取score
127.0.0.1:6379> ZSCORE weekday1 wed
"3"
指定索引返回元素:
127.0.0.1:6379> ZRANGE weekday1 0 2
1) "mon"
2) "tue"
3) "wed"
127.0.0.1:6379> ZRANGE weekday1 0 1
1) "mon"
2) "tue"
2.2.5 Hashed(映射)
外鍵指向整個映射,內鍵指明指定字段的值
查看幫助:
127.0.0.1:6379> help @hash
定義鍵:
127.0.0.1:6379> HSET h1 a mon
(integer) 1
獲取指定映射內,指定字段的值:
127.0.0.1:6379> HGET h1 a
"mon"
在映射內添加新字段並賦值:
127.0.0.1:6379> HSET h1 b tue
(integer) 1
127.0.0.1:6379> HGET h1 b
"tue"
獲取映射裏面的所有鍵:
127.0.0.1:6379> HKEYS h1
1) "a"
2) "b"
獲取映射裏面的所有元素(鍵值)
127.0.0.1:6379> HVALS h1
1) "mon"
2) "tue"
獲取映射裏面的元素個數
127.0.0.1:6379> HLEN h1
(integer) 2
二、其它應用
1、Redis認證功能
1.1 編輯配置
設置密碼為“redis123”
[root@node1 ~]# vim /etc/redis.conf
requirepass redis123
重啟服務:
[root@node1 ~]# service redis restart
Stopping redis-server: [ OK ]
Starting redis-server: [ OK ]
1.2 驗證
之前的默認連接方法:
[root@node1 ~]# redis-cli -h 10.201.106.21
10.201.106.21:6379> SELECT 0
(error) NOAUTH Authentication required.
認證:
10.201.106.21:6379> AUTH redis123
OK
10.201.106.21:6379> SELECT 0
OK
為了後面實驗方便,將上面密碼配置註釋掉,重啟服務,取消認證
2、Redis管理
2.1 清空數據庫:
FLUSHDB:清空當前庫
FLUSHALL:清空所有庫
127.0.0.1:6379> FLUSHDB
OK
2.2 事務(通過MULTI,EXEC,WATCH等命令實現事務功能)
2.2.1 事務示例
啟動一個事務:
127.0.0.1:6379> MULTI
OK
#不會馬上執行,而是放在隊列中
127.0.0.1:6379> SET ip 192.168.1.1
QUEUED
127.0.0.1:6379> GET ip
QUEUED
127.0.0.1:6379> SET port 8080
QUEUED
127.0.0.1:6379> GET port
QUEUED
事務執行(結果一並返回):
127.0.0.1:6379> EXEC
1) OK
2) "192.168.1.1"
3) OK
4) "8080"
2.2.2 WATCH(樂觀鎖演示)
ip鍵啟動樂觀鎖監控
127.0.0.1:6379> WATCH ip
OK
開啟事務:
127.0.0.1:6379> MULTI
OK
127.0.0.1:6379> set IP 10.0.0.1
QUEUED
127.0.0.1:6379> GET ip
QUEUED
然後在EXEC之前,新開一個redis客戶端窗口修改ip鍵的值:
127.0.0.1:6379> SET ip 172.16.0.1
OK
127.0.0.1:6379> get ip
"172.16.0.1"
回到第一個開啟事務的窗口執行EXEC,由於ip值已經發生修改,事務執行失敗
127.0.0.1:6379> EXEC
(nil) #事務未執行
2.2.3 一致性
127.0.0.1:6379> MULTI
OK
127.0.0.1:6379> GET ip
QUEUED
127.0.0.1:6379> SET port 6379
QUEUED
127.0.0.1:6379> SETT
(error) ERR unknown command ‘SETT‘
127.0.0.1:6379> EXEC
(error) EXECABORT Transaction discarded because of previous errors.
2.3 Redis的連接
2.3.1 PING
測試服務器是否在線
127.0.0.1:6379> PING
PONG
2.3.2 ECHO
127.0.0.1:6379> ECHO "hello redis"
"hello redis"
2.3.3 查看連接相關命令幫助
127.0.0.1:6379> help @connection
2.4 服務器端常用命令
2.4.1 查看幫助
127.0.0.1:6379> help @server
2.4.2 獲取當前客戶端連接名
連接沒有指定,所以為空
127.0.0.1:6379> CLIENT GETNAME
(nil)
2.4.3 關閉客戶端連接
127.0.0.1:6379> CLIENT KILL 127.0.0.1:49928
OK
2.4.4 設定當前連接名
127.0.0.1:6379> CLIENT SETNAME localconnect
OK
127.0.0.1:6379> CLIENT GETNAME
"localconnect"
2.4.5 獲取當前服務器狀態信息
127.0.0.1:6379> INFO
只顯示內存段信息:
127.0.0.1:6379> INFO Memory
# Memory
used_memory:657760
used_memory_human:642.34K
used_memory_rss:1716224
used_memory_peak:678504
used_memory_peak_human:662.60K
used_memory_lua:24576
mem_fragmentation_ratio:2.61
mem_allocator:jemalloc-3.6.0
重置info統計信息:
CONFIG RESETSTAT
2.4.6 修改配置
運行時修改指定參數,只保存在內存
CONFIG SET parameter value :
把在內存修改的新值同步到文件中
CONFIG REWRITE
2.4.7 查看鍵的數量
127.0.0.1:6379> DBSIZE
(integer) 2
2.4.8 獲取最新一次SAVE保存時間戳
127.0.0.1:6379> LASTSAVE
(integer) 1525450413
2.4.9 實時監控所接收的請求
127.0.0.1:6379> MONITOR
OK
2.4.10 把數據同步後,關閉服務
SHUTDOWN [SAVE]
3、Redis的發布訂閱
3.1 查看相關命令幫助
127.0.0.1:6379> HELP @pubsub
3.2 簡單示例
訂閱news頻道:
127.0.0.1:6379> SUBSCRIBE news
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "news"
3) (integer) 1
發布消息:
127.0.0.1:6379> PUBLISH news "heloow world"
(integer) 1
127.0.0.1:6379> PUBLISH news abc
(integer) 1
自動接收消息:
3.3 退訂頻道
UNSUBSCRIBE:退訂此前訂閱的頻道;
4、模式匹配
127.0.0.1:6379> PSUBSCRIBE "new.i[to]"
Reading messages... (press Ctrl-C to quit)
1) "psubscribe"
2) "new.i[to]"
3) (integer) 1
127.0.0.1:6379> PUBLISH new.io redis
(integer) 1
127.0.0.1:6379> PUBLISH new.it qq
(integer) 1
5、持久化
5.1 列出redis持久化備份目錄
127.0.0.1:6379> CONFIG GET dir
1) "dir"
2) "/var/lib/redis"
5.2 RDB持久化相關配置
RDB相關配置
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dbfilename dump.rdb
dir /var/lib/redis/
關閉RDB:
save ""
5.3 AOF持久化
5.3.1 AOF配置
#默認關閉
appendonly no
appendfilename "appendonly.aof"
appendfsync {always|everysec|no}
no-appendfsync-on-rewrite no
#達到兩倍開始重寫AOF文件
auto-aof-rewrite-percentage 100
#AOF文件達到64M才重寫
auto-aof-rewrite-min-size 64mb
5.4 備份恢復優先使用AOF備份
6、Redis復制(主從)
6.1 從服務器配置(node2)
安裝redis:
[root@node2 ~]# yum -y localinstall redis-3.0.7-4.el6.art.i686.rpm
修改監聽端口:
bind 10.201.106.22 127.0.0.1
服務啟動:
[root@node2 ~]# service redis start
Starting redis-server: [ OK ]
服務器配置SLAVE:
[root@node2 ~]# redis-cli
127.0.0.1:6379> SLAVEOF 10.201.106.21 6379
OK
現在node2已經是從服務器了
日誌查看:
[root@node2 ~]# tail -20 /var/log/redis/redis.log
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘
1694:M 14 Sep 04:35:05.444 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
1694:M 14 Sep 04:35:05.444 # Server started, Redis version 3.0.7
1694:M 14 Sep 04:35:05.444 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add ‘vm.overcommit_memory = 1‘ to /etc/sysctl.conf and then reboot or run the command ‘sysctl vm.overcommit_memory=1‘ for this to take effect.
1694:M 14 Sep 04:35:05.444 * The server is now ready to accept connections on port 6379
1694:S 14 Sep 04:36:03.912 * SLAVE OF 10.201.106.21:6379 enabled (user request from ‘id=2 addr=127.0.0.1:54185 fd=6 name= age=32 idle=0 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=32768 obl=0 oll=0 omem=0 events=r cmd=slaveof‘)
1694:S 14 Sep 04:36:04.156 * Connecting to MASTER 10.201.106.21:6379
1694:S 14 Sep 04:36:04.156 * MASTER <-> SLAVE sync started
1694:S 14 Sep 04:36:04.157 * Non blocking connect for SYNC fired the event.
1694:S 14 Sep 04:36:04.159 * Master replied to PING, replication can continue...
1694:S 14 Sep 04:36:04.160 * Partial resynchronization not possible (no cached master)
1694:S 14 Sep 04:36:04.196 * Full resync from master: d76cae20eecf731fd10f73a5498e61197a60e9de:1
1694:S 14 Sep 04:36:04.256 * MASTER <-> SLAVE sync: receiving 44 bytes from master
1694:S 14 Sep 04:36:04.256 * MASTER <-> SLAVE sync: Flushing old data
1694:S 14 Sep 04:36:04.256 * MASTER <-> SLAVE sync: Loading DB in memory
1694:S 14 Sep 04:36:04.256 * MASTER <-> SLAVE sync: Finished with success
主服務器配置
從服務器查看已經同步qq鍵值
清除主配置:
127.0.0.1:6379> FLUSHALL
OK
從庫空了:
127.0.0.1:6379> KEYS *
(empty list or set)
獲取從庫配置:
127.0.0.1:6379> CONFIG GET slaveof
1) "slaveof"
2) "10.201.106.21 6379"
註意:如果master使用requirepass開啟了認證功能,從服務器要使用masterauth <PASSWORD> 來連入服務器請求此密碼進行認證
7、sentinel(哨兵,監測主從)
7.1 sentinel配置準備
關閉node2的redis進程
[root@node2 ~]# killall redis-server
在node2服務器啟動三個redis進程,一個主庫,兩個從庫(相當於一臺機器啟動三個redis)
創建配置存放目錄:
[root@node2 ~]# mkdir -pv /etc/redis
拷貝配置文件到目錄:
[root@node2 ~]# cp /etc/redis.conf /etc/redis/
再拷貝2個配置文件,共3個配置文件:
[root@node2 redis]# cp redis.conf redis.conf.2
[root@node2 redis]# cp redis.conf redis.conf.3
[root@node2 redis]# ls
redis.conf redis.conf.2 redis.conf.3
準備存放數據目錄,並修改權限:
[root@node2 redis]# mkdir -pv /redis/db{1,2,3}
[root@node2 redis]# chown -R redis:redis /redis/db*
7.2 修改三個redis配置
第一個redis配置文件:
[root@node2 ~]# vim /etc/redis/redis.conf
#為了方便監聽在0.0.0.0,建議如果配置多個IP監聽,將外網IP配置在前面,127.0.0.1配置在後面,IP中間用空格隔開
bind 0.0.0.0
dir /redis/db1
#後面要用命令啟動,需要設置開啟進程運行後臺功能
daemonize yes
第二個redis配置文件:
[root@node2 ~]# vim /etc/redis/redis.conf.2
pidfile /var/run/redis/redis2.pid
port 6380
logfile /var/log/redis/redis2.log
dir /redis/db2
bind 0.0.0.0
daemonize yes
第三個redis配置文件:
拷貝redis.conf.2配置文件覆蓋redis.conf.3
[root@node2 ~]# cd /etc/redis
[root@node2 redis]# cp redis.conf.2 redis.conf.3
[root@node2 ~]# vim /etc/redis/redis.conf.3
pidfile /var/run/redis/redis3.pid
port 6381
logfile /var/log/redis/redis3.log
dir /redis/db3
daemonize yes
7.3 啟動服務,並配置sentinel
啟動第一個redis(主服務器):
[root@node2 ~]# redis-server /etc/redis/redis.conf
啟動第二個redis(從服務器):
[root@node2 ~]# redis-server /etc/redis/redis.conf.2
啟動第三個redis(從服務器):
[root@node2 ~]# redis-server /etc/redis/redis.conf.3
[root@node2 ~]# ss -tnlp | grep redis
LISTEN 0 128 *:6379 *:* users:(("redis-server",19377,4))
LISTEN 0 128 *:6380 *:* users:(("redis-server",19391,4))
LISTEN 0 128 *:6381 *:* users:(("redis-server",19397,4))
7.4 連接配置
連接主服務器檢查狀態是不是主服務器:
[root@node2 ~]# redis-cli -h 10.201.106.22 -p 6379
10.201.106.22:6379> info replication
# Replication
role:master
……
第一個從服務器配置:
[root@node2 ~]# redis-cli -h 10.201.106.22 -p 6380
配置向哪個主服務器進行同步
10.201.106.22:6380> SLAVEOF 10.201.106.22 6379
OK
第二個從服務器配置:
10.201.106.22:6381> SLAVEOF 10.201.106.22 6379
OK
主服務器查看狀態:
10.201.106.22:6379> info replication
10.201.106.22:6379> info replication
# Replication
role:master
connected_slaves:2
slave0:ip=10.201.106.22,port=6380,state=online,offset=211,lag=1
slave1:ip=10.201.106.22,port=6381,state=online,offset=211,lag=0
……
7.5 測試同步
10.201.106.22:6379> SET ip 1.1.1.1
OK
查看已經能夠正常同步:
10.201.106.22:6380> GET ip
"1.1.1.1"
10.201.106.22:6381> GET ip
"1.1.1.1"
7.6 sentinel監控主節點
準備配置文件:
[root@node2 ~]# cp /etc/redis-sentinel.conf /etc/redis/
[root@node2 ~]# vim /etc/redis/redis-sentinel.conf
#一個哨兵同意,就確定為故障
sentinel monitor mymaster 10.201.106.22 6379 1
#設置5秒檢查不到主服務器,就將其down掉
sentinel down-after-milliseconds mymaster 5000
#並行度為1
sentinel parallel-syncs mymaster 1
#判斷故障轉移失敗超時時間
sentinel failover-timeout mymaster 60000
啟動sentinel服務:
[root@node2 ~]# redis-sentinel /etc/redis/redis-sentinel.conf
連入sentinel:
[root@node2 ~]# redis-cli -h 10.201.106.22 -p 26379
查看配置信息:
10.201.106.22:26379> info
獲取master信息:
10.201.106.22:26379> SENTINEL masters
1) 1) "name"
2) "mymaster"
3) "ip"
4) "10.201.106.22"
5) "port"
6) "6379"
7) "runid"
8) "6afb08c6e2369213825dc8c08ca0fafede756569"
9) "flags"
10) "master"
11) "pending-commands"
12) "0"
13) "last-ping-sent"
14) "0"
15) "last-ok-ping-reply"
16) "603"
17) "last-ping-reply"
18) "603"
19) "down-after-milliseconds"
20) "5000"
21) "info-refresh"
22) "8121"
23) "role-reported"
24) "master"
25) "role-reported-time"
26) "521577"
27) "config-epoch"
28) "0"
29) "num-slaves"
30) "2"
31) "num-other-sentinels"
32) "0"
33) "quorum"
34) "1"
35) "failover-timeout"
36) "60000"
37) "parallel-syncs"
38) "1"
查看從節點服務器:
10.201.106.22:26379> SENTINEL slaves mymaster
7.7 故障轉移測試
kill主服務器進程:
[root@node2 ~]# ps aux | grep 6379
root 19377 0.1 0.3 33920 1748 ? Ssl 05:53 0:04 redis-server 0.0.0.0:6379
[root@node2 ~]# kill 19377
在哨兵查看,6380端口(原第一從服務器)已經變成主服務器:
10.201.106.22:26379> INFO Sentinel
# Sentinel
sentinel_masters:1
sentinel_tilt:0
sentinel_running_scripts:0
sentinel_scripts_queue_length:0
master0:name=mymaster,status=ok,address=10.201.106.22:6380,slaves=2,sentinels=1
查看主節點信息:
10.201.106.22:26379> SENTINEL masters
重新啟動10.201.106.22:6379(原主服務器)
[root@node2 ~]# redis-server /etc/redis/redis.conf
再次查看,不會切換,主節點還是6380端口:
10.201.106.22:26379> INFO Sentinel
10.201.106.22:26379> SENTINEL slaves mymaster
8、Clustering(分片)
分布式解決方案:
Twemproxy(Twitter),不建議使用
Codis(豌豆莢,豆瓣),建議使用
Redis Cluster(官方)
Cerberus(芒果TV)
Redis雜記