一、部署三主三从的Redis集群

分别为6个节点建立挂载目录，每个目录下建立数据、配置、日志文件夹。

docker-compose内容如下：

version: '3'
services:
  redis1:
    image: redis:6.2.3
    restart: always
    ports:
      - "6379:6379"
      - "16379:16379"
    volumes:
      - "./6379/data:/data/redis"
      - "./6379/logs:/opt/redis/logs"
      - "./6379/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf
  redis2:
    image: redis:6.2.3
    restart: always
    ports:
      - "6380:6380"
      - "16380:16380"
    volumes:
      - "./6380/data:/data/redis"
      - "./6380/logs:/opt/redis/logs"
      - "/opt/redis/cluster/6380/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf
  redis3:
    image: redis:6.2.3
    restart: always
    ports:
      - "6381:6381"
      - "16381:16381"
    volumes:
      - "./6381/data:/data/redis"
      - "./6381/logs:/opt/redis/logs"
      - "./6381/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf
  redis4:
    image: redis:6.2.3
    restart: always
    ports:
      - "7379:7379"
      - "17379:17379"
    volumes:
      - "./7379/data:/data/redis"
      - "./7379/logs:/opt/redis/logs"
      - "./7379/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf
  redis5:
    image: redis:6.2.3
    restart: always
    ports:
      - "7380:7380"
      - "17380:17380"
    volumes:
      - "./7380/data:/data/redis"
      - "./7380/logs:/opt/redis/logs"
      - "./7380/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf
  redis6:
    image: redis:6.2.3
    restart: always
    ports:
      - "7381:7381"
      - "17381:17381"
    volumes:
      - "./7381/data:/data/redis"
      - "./7381/logs:/opt/redis/logs"
      - "./7381/etc/redis.conf:/etc/redis/redis.conf"
    command: redis-server /etc/redis/redis.conf

 redis.conf大同小异，以redis1的配置为例，大部分是默认配置值，主要是修改集群配置部分，和端口部分

bind 0.0.0.0
protected-mode no
# 每个实例有各自的端口，6380,6381等等
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize no

pidfile /var/run/redis.pid
loglevel verbose
logfile "/opt/redis/logs/redis.log"
always-show-logo no

set-proc-title yes
proc-title-template "{title} {listen-addr} {server-mode}"
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes

dbfilename dump.rdb
rdb-del-sync-files no
dir /data/redis/

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
requirepass 123456
maxmemory 10737418240

lazyfree-lazy-eviction no
lazyfree-lazy-expire no
lazyfree-lazy-server-del no
replica-lazy-flush no

lazyfree-lazy-user-del no

lazyfree-lazy-user-flush no

oom-score-adj no
oom-score-adj-values 0 200 800
disable-thp yes

appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb

aof-load-truncated yes
aof-use-rdb-preamble yes

lua-time-limit 5000

# 集群关键配置
cluster-enabled yes
cluster-config-file nodes-6379.conf
cluster-node-timeout 15000


cluster-announce-ip 172.19.23.214
#每个实例改为各自对应的端口
cluster-announce-port 6379
cluster-announce-bus-port 16379

slowlog-log-slower-than 10000
slowlog-max-len 128
latency-monitor-threshold 0
notify-keyspace-events Ex
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

stream-node-max-bytes 4096
stream-node-max-entries 100

activerehashing yes
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit replica 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60

hz 10
dynamic-hz yes
aof-rewrite-incremental-fsync yes
rdb-save-incremental-fsync yes
jemalloc-bg-thread yes

使用docker-compose up -d 启动集群，查看状态是否正常，如果启动失败可以查看6379/logs/redis.log查看日志。

进入redis的bin目录下执行，（也可以进入任意一个容器内执行）

./redis-cli --cluster create -a 123456 172.16.19.234:6379 172.16.19.234:7379 172.16.19.234:6380 172.16.19.234:7380 172.16.19.234:6381 172.16.19.234:7381 --cluster-replicas 1

命令会输出一段提示，输入yes同意集群配置，稍等片刻显示成功，这个过程不需要太久（不到一分钟），如果等了很久一直显示......，那就是有问题，但是控制台不会报错，要检查配置、日志看是否有问题。

配置成功后，连接集群

./redis-cli  -c  -h 172.16.19.234 -p 6379 -a 123456

 查看集群信息

查看集群节点

测试命令，根据键值所在槽位，会自动切换到对应节点的连接。

集群模式不支持select 选数据库，只有0号

 二、数据迁移

 安装redis-dump

npm install redis-dump -g

也有的教程是用

apt-get install ruby ruby-dev gcc
sudo gem install redis-dump

 安装的，不知道有什么区别，我两种方式都安装了。

导出：

# -d 表示几号数据库
redis-dump -u 172.16.19.234:6379 -a 123456 -d 0 > data0.json

导入：

cat data0.json | bin/redis-cli -c  -h 172.16.19.234 -p 6379 -a 123456

最后使用dbsize命令检查迁移数据是否完整。集群要把每个节点的总和加起来。