Detailed explanation of Redis master-slave replication practice using Docker

1. Background

I'm currently working on a zero-trust security gateway and need to use Redis as an authentication cache server. Because the gateway servers are distributed in multiple clusters, cross-computer room authentication is not easy to implement each time. Therefore, I need to use Redis master-slave synchronization and record the process. I hope this can provide some reference for students in need.

2. Operation steps

• Install Docker
• Main service configuration
• From the service configuration
• Verify the synchronization effect

3. Install Docker

This article mainly asks about the process of recording master-slave configuration, so I use the simplest docker method to build the Redis service. The command to install docker is as follows

curl -sSL https://get.daocloud.io/docker | sh

After the command is executed, you can see the interface shown in the following figure

In the above picture, you can see some relevant information about docker. To confirm whether docker is installed successfully, you can also use the docker info command to check. The execution command is as follows

docker info

After the command is executed, the returned information is as shown in the figure below

In the above picture, you can see that the version information of Docker is 20.10.3, which is the latest version at present. It has been confirmed that the installation is successful.

4. Main Service Configuration

Next, I need to use docker to install the Redis service. In practice, I found that using the Redis image directly was a bit abnormal, so I used the centos image and installed Redis in the container. The command to run the container is as follows

docker run -d -it -p 16379:6379 --name redis_master centos:7

After the command is executed, enter the container. The command to enter the container is as follows

docker exec -it redis_master bash

After the command is executed, the returned information is as shown in the figure below

In the above picture, you can see that you have successfully entered the container. Next, I need to install Redis in the container. The command to install Redis is as follows

yum install -y epel-release && yum install -y redis

After the command is executed, the returned information is as shown in the figure below

As you can see from the above figure, Redis has been installed. Next, you need to create a new Redis master library configuration file. The execution command is as follows

vi ~/master.conf

The configuration file is as follows. Copy and paste the following configuration file into the vi editing window.

#bind 0.0.0.0
protected-mode yes
port 6379
tcp-backlog 511
unixsocket /tmp/redis_auth.sock
unixsocketperm 777
timeout 0
tcp-keepalive 300
daemonize yes
supervised auto
pidfile /var/run/redis_auth.pid
loglevel debug
logfile /tmp/redis_auth.log
databases 16
save ""
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dbfilename dump.rdb
dir /var/lib/redis
requirepass 123123123
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no
slave-priority 100
appendonly yes
appendfilename "funfe.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 512mb
aof-load-truncated yes
lua-time-limit 5000
slowlog-log-slower-than 10000
slowlog-max-len 128
latency-monitor-threshold 0
notify-keyspace-events ""
hash-max-ziplist-entries 512
hash-max-ziplist-value 64
list-max-ziplist-size -2
list-compress-depth 0
set-max-intset-entries 512
zset-max-ziplist-entries 128
zset-max-ziplist-value 64
hll-sparse-max-bytes 3000
activerehashing yes
hz 10
aof-rewrite-incremental-fsync yes

After pasting in the vi editing window, it is as shown below

After pasting and checking, use the :wq! command to save, and then you can start the Redis program. The startup command is as follows

redis-server `/redis.conf

In the startup command above, you need to specify the configuration file path, as shown in the figure below

In the above figure, you can see that the Redis service has been started.

5. From service configuration

Next, I need to start a Redis slave server again. The command to run the container is as follows

docker run -d -it -p 26379:6379 --name redis_slave centos:7

In the command above, because it is on the same host, in order not to conflict with the master library port, I set the host port to 26379. After the startup is complete, you can enter the slave library container. The command to run is as follows

docker exec -it redis_slave bash

After the command is executed, you also need to create a new Redis configuration file. The command to run is as follows

vi ~/redis.conf

In the configuration file, you need to add the configuration code of the slave library. The configuration sample is as follows

bind 127.0.0.1
protected-mode yes
port 6379
tcp-backlog 511
unixsocket /tmp/redis_auth.sock
unixsocketperm 777
timeout 0
tcp-keepalive 300
daemonize yes
supervised auto
pidfile /var/run/redis_6379.pid
loglevel notice
logfile /tmp/redis.log
databases 16
save ""
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dbfilename dump.rdb
dir /var/lib/redis
slaveof 172.23.193.148 16379
masterauth 123123123
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no
slave-priority 100
appendonly yes
appendfilename "funfe.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 512mb
aof-load-truncated yes
lua-time-limit 5000
slowlog-log-slower-than 10000
slowlog-max-len 128
latency-monitor-threshold 0
notify-keyspace-events ""
hash-max-ziplist-entries 512
hash-max-ziplist-value 64
list-max-ziplist-size -2
list-compress-depth 0
set-max-intset-entries 512
zset-max-ziplist-entries 128
zset-max-ziplist-value 64
hll-sparse-max-bytes 3000
activerehashing yes
hz 10
aof-rewrite-incremental-fsync yes

After copying the configuration sample, the window will look like this:

After pasting and checking, use the :wq! command to save, then you can start the Redis program. The startup command is as follows. Then install the Redis service. The installation command is as follows

yum install -y epel-release && yum install -y redis

After the command is executed, the returned information is as shown in the figure below

In the figure above, you can see that the Redis of the slave library has also been installed. Next, use the redis-server command to start the slave library server. The command is shown in the figure below

redis-server redis.conf

After the command is executed, the returned information is as shown in the figure below

In the above picture, you can see that Redis has been started. Next, you can verify the effect.

6. Result Verification

The verification method is mainly to set data in the master database and observe whether the slave database is also updated synchronously;

6.1 Preliminary Verification

However, this operation is a bit troublesome. We'd better check the startup log of the slave library first. The command to check the startup log is as follows

cat /tmp/redis.log

After the command is executed, Redis log information will be returned, as shown in the following figure

From the log information in the figure above, you can see that the slave library has successfully copied the master library information to the local.

6.2 Synchronization Check

Although the log indicates success, whether the master-slave synchronization is successful still depends on the actual effect. Here I return to the terminal window of the master server and enter the redis command console. The command to enter the console is as follows

redis-cli -a 123123123

After the command is executed, you can perform redis command operations. Here I set a key-value pair of test as 123123. The setting command is as follows

set test 123123

After the command is executed, the returned information is as shown in the figure below

In the figure above, you can see that Redis has prompted that the key-value pair has been set successfully. Next, I will go back to the terminal window of the slave library, enter the Redis console, and execute the command as follows

redis-cli -a 123123123

After the command is executed, you can view the key-value pairs of the current slave library through the keys command. The command is as follows
keys *

After the command is executed, the returned information is as shown in the figure below

In the figure above, you can see that the test data has been successfully copied.

This is the end of this article about using Docker for Redis master-slave replication. For more information about Docker Redis master-slave replication, please search for previous articles on 123WORDPRESS.COM or continue to browse the following related articles. I hope you will support 123WORDPRESS.COM in the future!