Redis主从复制多实例及其高可用--技术流ken

Posted kenken2018

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Redis主从复制

Redis的主从复制策略是通过其持久化的rdb文件来实现的,其过程是先dump出rdb文件,将rdb文件全量传输给slave,然后再将dump后的操作实时同步到slave中。让从服务器(slave server)成为主服务器(master server)的精确复制品。

 

Redis主从复制的实现

首先需要准备两台服务器,两台都要安装redis程序

主服务器IP: 10.220.5.137

从服务器IP: 10.220.5.138

 

第一步:安装redis(主从两端都要操作)

[[email protected] html]# yum install redis -y

 

第二步:启动redis(主从两端都要操作)

[[email protected] html]# systemctl restart redis

 

第三步:修改配置文件(主从两端都要操作)

大约在61行处,修改绑定的IP地址为本机IP

 #
  47 # bind 192.168.1.100 10.0.0.1
  48 # bind 127.0.0.1 ::1
  49 #
  50 # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
  51 # internet, binding to all the interfaces is dangerous and will expose the
  52 # instance to everybody on the internet. So by default we uncomment the
  53 # following bind directive, that will force Redis to listen only into
  54 # the IPv4 lookback interface address (this means Redis will be able to
  55 # accept connections only from clients running into the same computer it
  56 # is running).
  57 #
  58 # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
  59 # JUST COMMENT THE FOLLOWING LINE.
  60 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  61 bind 10.220.5.137
  62 
  63 # Protected mode is a layer of security protection, in order to avoid that
  64 # Redis instances left open on the internet are accessed and exploited.
  65 #
  66 # When protected mode is on and if:
  67 #
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet, binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive, that will force Redis to listen only into
# the IPv4 lookback interface address (this means Redis will be able to
# accept connections only from clients running into the same computer it
# is running).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bind 10.220.5.138

# Protected mode is a layer of security protection, in order to avoid that
# Redis instances left open on the internet are accessed and exploited.
#
# When protected mode is on and if:
#
# 1) The server is not binding explicitly to a set of addresses using the
#    "bind" directive.
# 2) No password is configured.

 

第四步:重启redis(主从两端都要操作)

[[email protected] html]# systemctl restart redis

 

第五步:登录redis

修改了绑定的地址之后需要指定本机的IP地址才能登录

[[email protected] html]# redis-cli -h 10.220.5.138

 

第六步:实现主从复制

10.220.5.138:6379> SLAVEOF 10.220.5.137 6739
OK

 

第七步:查看

 在主服务器端查看所有的key

10.220.5.137:6379> keys *
1) "gender"
2) "ken"
3) "tel"
4) "ad"
5) "kenken"
6) "name"
7) "myha"
8) "addr"

在从服务器端查看所有的key.可以看到已经复制过来了

10.220.5.138:6379> keys *
1) "name"
2) "ken"
3) "kenken"
4) "addr"
5) "myha"
6) "ad"
7) "tel"
8) "gender"

 

Redis的多实例

顾名思义多实例就是一台服务器上安装多个redis服务器,这样可以更大程度的利用有限资源,在做一些实验的时候也是强烈建议使用多实例的方式,以节省内存消耗。下面就来看一下如何实现多实例吧。

 

Redis实现多实例

第一步:创建目录

准备在10.220.5.137服务器端创建三个实例6379 6380 6381

[[email protected] ~]# mkdir /redis/{6379,6380,6381} -p

 

第二步:复制配置文件到三个目录之下

[[email protected] ~]# cp /etc/redis.conf /redis/6379/
[[email protected] ~]# cp /etc/redis.conf /redis/6380/
[[email protected] ~]# cp /etc/redis.conf /redis/6381/

 

第三步:修改每个目录之下的配置文件

6379端口实例配置

[[email protected] ~]# egrep -v ^#|^$ /redis/6379/redis.conf
bind 10.220.5.137
protected-mode yes
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize no
supervised no
pidfile /redis/6379/redis_6379.pid
loglevel notice
logfile /redis/6379/redis.log
...

6380端口实例配置

[[email protected] ~]# egrep -v ^#|^$ /redis/6380/redis.conf
bind 10.220.5.137
protected-mode yes
port 6380
tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize no
supervised no
pidfile /redis/6380/redis_6379.pid
loglevel notice
logfile /redis/6380/redis.log
databases 16
save 900 1
save 300 10
save 60 10000
....

6381端口实例配置

[[email protected] ~]# egrep -v ^#|^$ /redis/6381/redis.conf
bind 10.220.5.137
protected-mode yes
port 6381
tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize no
supervised no
pidfile /redis/6381/redis_6379.pid
loglevel notice
logfile /redis/6381/redis.log
databases 16
save 900 1
save 300 10
save 60 10000
....

 

第四步:启动后台运行

大约在128行处修改为yes,三个配置文件都需要修改

...
# By default Redis does not run as a daemon. Use yes if you need it. 127 # Note that Redis will write a pid file in /var/run/redis.pid when daemonized. 128 daemonize yes 129 130 # If you run Redis from upstart or systemd, Redis can interact with your 131 # supervision tree. Options:
...

 

第五步:启动多实例

[[email protected] ~]# redis-server /redis/6379/redis.conf 
[[email protected] ~]# redis-server /redis/6380/redis.conf 
[[email protected] ~]# redis-server /redis/6381/redis.conf 
[[email protected] ~]# ss -tnl
State       Recv-Q Send-Q  Local Address:Port                 Peer Address:Port              
LISTEN      0      128                 *:10050                           *:*                  
LISTEN      0      128      10.220.5.137:6379                            *:*                  
LISTEN      0      128      10.220.5.137:6380                            *:*                  
LISTEN      0      128      10.220.5.137:6381                            *:*                  
LISTEN      0      128                 *:111                             *:*                  
LISTEN      0      128                 *:22                              *:*                  
LISTEN      0      128                :::10050                          :::*                  
LISTEN      0      128                :::111                            :::*                  
LISTEN      0      128                :::80                             :::*                  
LISTEN      0      128                :::22                             :::*     

至此多实例已经配置成功

 

Redis的高可用

redis高可用即主节点出现故障时,从节点会接替主节点,这个时候从节点就变成了主节点,实现redis的高可用。

 

接着上面配置好的多实例,现在我们来实现redis的高可用

主节点:10.220.5.137:6379

从1节点:10.220.5.137:6380

从2节点:10.220.5.138:6381

监控端:10.220.5.138

 

第一步:从节点指向主节点

从1节点

[[email protected] ~]# redis-cli -h 10.220.5.137 -p 6380
10.220.5.137:6380> SLAVEOF 10.220.5.137 6379
OK
10.220.5.137:6380> exit

从2节点

[[email protected] ~]# redis-cli -h 10.220.5.137 -p 6381
10.220.5.137:6381> SLAVEOF 10.220.5.137 6379
OK
10.220.5.137:6381> exit

 

第二步:在主节点查看

可以看到如下信息role为master.连接的slave端为2个

[[email protected] ~]# redis-cli -h 10.220.5.137 -p 6379
10.220
.5.137:6379> info replication # Replication role:master connected_slaves:2 slave0:ip=10.220.5.137,port=6380,state=online,offset=365,lag=0 slave1:ip=10.220.5.137,port=6381,state=online,offset=365,lag=1 master_repl_offset:365 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:2 repl_backlog_histlen:364

 

第三步:修改监控端的配置文件

 只需要修改17行关闭保护模式,以及69行处,添加主节点信息即可

[[email protected] html]# vim /etc/redis-sentinel.conf 

   15 # bind 127.0.0.1 192.168.1.1
   16 #
   17 protected-mode no
   18
   19 # port <sentinel-port>
   20 # The port that this sentinel instance will run on
   21 port 26379


...
 67 # Note: master name should not include special characters or spaces.
 68 # The valid charset is A-z 0-9 and the three characters ".-_".
 69 sentinel monitor mymaster 10.220.5.137 6379 1
 70 
 71 # sentinel auth-pass <master-name> <password>
 72 #
...

 

第四步:启动监控节点

sentinel监控的是26379

[[email protected] html]# systemctl restart redis-sentinel
[[email protected] html]# ss -tnl
State       Recv-Q Send-Q  Local Address:Port                 Peer Address:Port              
LISTEN      0      128                 *:10050                           *:*                  
LISTEN      0      128                 *:26379                           *:*                  
LISTEN      0      128      10.220.5.138:6379                            *:*                  
LISTEN      0      128                 *:111                             *:*                  
LISTEN      0      128                 *:22                              *:*                  
LISTEN      0      128                :::10050                          :::*                  
LISTEN      0      128                :::26379                          :::*                  
LISTEN      0      128                :::111                            :::*                  
LISTEN      0      128                :::80                             :::*                  
LISTEN      0      128                :::22                             :::*       

 

第五步:登录监控端

[[email protected] html]# redis-cli -h 10.220.5.138 -p 26379

 

第六步:查看主服务端信息

现在可以看到主服务器端节点为10.220.5.137,端口号为6379

10.220.5.138:26379> sentinel masters
1)  1) "name"
    2) "mymaster"
    3) "ip"
    4) "10.220.5.137"
    5) "port"
    6) "6379"
    7) "runid"
    8) "1096f9bef5606124ddd437f93e3c7d5027061abf"
    9) "flags"
   10) "master"
   11) "link-pending-commands"
   12) "0"
   13) "link-refcount"
   14) "1"
   15) "last-ping-sent"
   16) "0"
...

 

第七步:查看从服务器点状态

这里会看到所有的从节点信息

10.220.5.138:26379> sentinel slaves mymaster
1)  1) "name"
    2) "10.220.5.137:6380"
    3) "ip"
    4) "10.220.5.137"
    5) "port"
    6) "6380"
    7) "runid"
    8) "bc8524006a66bfee2aaa15d3b5615fb0cdb50cb1"
    9) "flags"
   10) "slave"
   11) "link-pending-commands"
   12) "0"
   13) "link-refcount"
   14) "1"
   15) "last-ping-sent"
   16) "0"
   17) "last-ok-ping-reply"
   18) "521"
   19) "last-ping-reply"
   20) "521"
   21) "down-after-milliseconds"
   22) "30000"
   23) "info-refresh"
   24) "8370"
   25) "role-reported"
...

 

Redis高可以用测试

 第一步:关闭主服务器节点

[[email protected] ~]# ps aux | grep redis
root      4403  0.2  0.4 142952  2240 ?        Rsl  20:50   0:01 redis-server 10.220.5.137:6379
root      4408  0.1  0.4 142952  2248 ?        Ssl  20:50   0:01 redis-server 10.220.5.137:6380
root      4413  0.1  0.4 142952  2248 ?        Ssl  20:50   0:01 redis-server 10.220.5.137:6381
root      4457  0.0  0.1 112704   968 pts/0    S+   21:04   0:00 grep --color=auto redis
[[email protected] ~]# kill -9 4403
[[email protected] ~]# ps aux | grep redis
root      4408  0.1  0.4 142952  2264 ?        Ssl  20:50   0:01 redis-server 10.220.5.137:6380
root      4413  0.1  0.4 142952  2264 ?        Ssl  20:50   0:01 redis-server 10.220.5.137:6381
root      4459  0.0  0.1 112704   964 pts/0    R+   21:04   0:00 grep --color=auto redis

 

第二步:在监控节点查看主服务器端节点状态.

可以看到现在的主服务器节点已经变成10.220.5.137端口号为6380

10.220.5.138:26379> sentinel masters
1)  1) "name"
    2) "mymaster"
    3) "ip"
    4) "10.220.5.137"
    5) "port"
    6) "6380"
    7) "runid"
    8) "bc8524006a66bfee2aaa15d3b5615fb0cdb50cb1"
    9) "flags"
   10) "master"
   11) "link-pending-commands"
   12) "0"
   13) "link-refcount"
   14) "1"
   15) "last-ping-sent"
   16) "0"
   17) "last-ok-ping-reply"
   18) "777"
   19) "last-ping-reply"
   20) "777"
   21) "down-after-milliseconds"
   22) "30000"
   23) "info-refresh"
...

 













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