Docker integrates the redis sentinel mode (one master, two slave and three sentinels)

docker Integrate redis Sentinel mode ( One leader, two followers and three sentinels )

Redis-Sentinel yes Redis Official recommended high availability (HA) Solution , When used Redis do Master-slave The high availability of , If master It's down. ,Redis In itself ( Including many of its clients ) No automatic master / standby switching is realized , and Redis-sentinel It is also an independent process , It can monitor multiple master-slave colony , Find out master Can be automatically switched after downtime .Sentinel By one or more Sentinel example Composed of Sentinel The system can monitor any number of primary servers , And all the slave servers under these master servers , And when the monitored master server goes offline , Automatically upgrade a slave server under the offline master server to a new master server . 

 

Let's start with the principle ：  Pictured above , This is the structure of sentinel mode , Only master Can be done write, The others didn't write Authority , Only read jurisdiction , When master After the failure , A new one will be elected master, And the Sentry will put the new master The address is returned to the project , So that the project can quickly switch to the new master, The following figure shows the switched architecture .

 

Let's start building docker sentinel Sentinel mode

Encounter pit ： use docker swarm Integrate setinel , master Failure cannot be switched automatically , because sentinel From monitoring master obtain slave Of ip yes docker The virtual ip, NAT Unable to switch due to impassability . The following is to use docker run To build . The public network is adopted ip

 

Prepare three hosts ： Deploy one on each of the three machines redis And a sentinel, To achieve high availability

1, start-up master node

docker run -it --name redis-master -v /home/AuthenticationCenter/redis/master:/data  -d -p 6379:6379 --network=cloud_desktop_network  redis:5.0

notes ： Network initialization  --attachable The network of patterns , The network can be in docker swarm The cluster is free to add other containers , Later in the project, you can pass Container name visit .

2, Start the second and third slave nodes

docker run -it --name redis-slave-1 -v /home/AuthenticationCenter/redis/slave1:/data  -d -p 6380:6379 --network=cloud_desktop_network  redis:5.0  redis-server --slaveof 121.201.95.75 6379 --slave-announce-ip 121.201.75.49 --slave-announce-port 6380 

explain ：--slaveof 121.201.95.75 6379   To configure master Address ,

         --slave-announce-ip 121.201.75.49   To configure slave Tell the sentry slave Address

         --slave-announce-port 6380  To configure slave Tell the sentry slave The port of

 3, Activate the sentry sentinel

Copy three copies as sentinel1.conf , sentinel2.conf , sentinel3.conf ,   Because the ports started in the container are 26379 , It's all monitoring master node , So the three configurations are the same ,

Execute the following command , Copy 3 Share redis-sentinel The configuration file

cp sentinel.conf sentinel1.conf
cp sentinel.conf sentinel2.conf
cp sentinel.conf sentinel3.conf

sentinel.conf as follows ： 

port 26379
dir /tmp
#  Custom cluster name , among  121.201.95.75  by  redis-master  Of  ip,6379  by  redis-master  The port of ,2  Is the minimum number of votes （ Because there is  3  platform  Sentinel  So it can be set to  2）
sentinel monitor mymaster 121.201.95.75 6379 2
sentinel down-after-milliseconds mymaster 30000
sentinel parallel-syncs mymaster 1
# configure connections master Password 
sentinel auth-pass mymaster [email protected]
sentinel failover-timeout mymaster 180000
sentinel deny-scripts-reconfig yes

problem ： Many people are curious , Monitor only master,  slave How to monitor ,

answer ：slave It's through master Back to ip Just listen .

 

Start three sentinels on three servers （ One sentry per server ）, Play the role of disaster recovery , Distributed deployment

start-up sentinel-1 command ：docker run -it --name redis-sentinel-1 -v /home/AuthenticationCenter/redis/docker/sentinel/sentinel1.conf:/usr/local/etc/redis/sentinel.conf  -d -p 26379:26379 --network=cloud_desktop_network  redis:5.0  redis-sentinel /usr/local/etc/redis/sentinel.conf

start-up sentinel-2 command ：docker run -it --name redis-sentinel-2 -v /home/AuthenticationCenter/redis/docker/sentinel/sentinel2.conf:/usr/local/etc/redis/sentinel.conf  -d -p 26380:26379 --network=cloud_desktop_network  redis:5.0  redis-sentinel /usr/local/etc/redis/sentinel.conf

start-up sentinel-3 command ：docker run -it --name redis-sentinel-3 -v /home/AuthenticationCenter/redis/docker/sentinel/sentinel3.conf:/usr/local/etc/redis/sentinel.conf  -d -p 26381:26379 --network=cloud_desktop_network  redis:5.0  redis-sentinel /usr/local/etc/redis/sentinel.conf

4, Check whether the status is successful after configuration  

     1, Check the sentinel status （ Here's the picture ）

  Enter one of the Sentinels ： docker exec -it Containers id /bin/bash 

Get into redis-server : redis-cli -p 26379

see master Of host situation ：sentinel slaves mymaster         Here's the picture , This is successful , There are indications ip, ok identification

 

  2, Connect three sets redis , The manual in master Write data , see slave Is it synchronized .

1 and 2 It's normal redis The sentry is finished ,

 

4, old master How to join after hanging up redis Cluster ,

    Find out at this time master Node ip, adopt salve Just join by

 

5,springboot How to use the project ？

  It's very simple , Only need to configure sentinels ip And port , Here's the picture ：

 1, add to maven rely on

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.1.5.RELEASE</version>
        </dependency>

2, add to redis To configure

#redis
spring.redis.database=0
#spring.redis.password=
# List of sentinels ,master The address Sentry will automatically return 
spring.redis.sentinel.master=mymaster
spring.redis.sentinel.nodes=39.107.119.256:26379,39.107.119.256:26380,39.107.119.256:26381
# The maximum number of connections to the database , set up  0  For there is no limit 
spring.redis.lettuce.pool.max-active=8
# Maximum number of waiting connections , set up  0  For there is no limit 
spring.redis.lettuce.pool.max-idle=8
# Maximum connection setup wait time . If this time is exceeded, an exception will be received . Set to -1 Means unlimited .
spring.redis.lettuce.pool.max-wait=-1ms
# Minimum number of waiting connections , set up  0  For there is no limit 
spring.redis.lettuce.pool.min-idle=0
spring.redis.lettuce.shutdown-timeout=100ms

Here we are ,docker Integrate redis Sentinel cluster complete