Redis集群
1.烧饼的不足
1.主库写压力太大
2.资源利用率不高
3.连接过程繁琐，效率低
2.集群的重要概念
1.Redis集群，无论有几个节点，一共只有16384个槽位
2.所有的槽都必须被正确分配，哪怕有1个槽不正常，整个集群都不可用
3.每个节点的槽的顺序不重要，重要的是槽的数量
4.HASH算法足够平均，足够随机
5.每个槽被分配到数据的概率是大致相当的
6.集群的高可用依赖于主从复制
7.集群节点之间槽位的数量允许在2%的误差范围内
8.集群通讯会使用基础端口号+10000的端口，自动创建的，不是配置文件配置的，生产要注意的是防火墙注意要放开此端口
3.目录规划
主节点 6380
从节点 6381
4.db01的操作
#1.发送SSH认证，方便后面传输
ssh-keygen
ssh-copy-id 10.0.0.52
ssh-copy-id 10.0.0.53
#2.创建目录
pkill redis
mkdir -p /opt/redis_{6380,6381}/{conf,logs,pid}
mkdir -p /data/redis_{6380,6381}
#3.生成主节点配置文件
cat >/opt/redis_6380/conf/redis_6380.conf<<EOF
bind 10.0.0.51
port 6380
daemonize yes
pidfile "/opt/redis_6380/pid/redis_6380.pid"
logfile "/opt/redis_6380/logs/redis_6380.log"
dbfilename "redis_6380.rdb"
dir "/data/redis_6380/"
appendonly yes
appendfilename "redis.aof"
appendfsync everysec
cluster-enabled yes
cluster-config-file nodes_6380.conf
cluster-node-timeout 15000
EOF
#4.复制主节点的配置文件到从节点并更改端口号
cd /opt/
cp redis_6380/conf/redis_6380.conf redis_6381/conf/redis_6381.conf
sed -i 's#6380#6381#g' redis_6381/conf/redis_6381.conf
#5.更改授权为redis
chown -R redis:redis /opt/redis_*
chown -R redis:redis /data/redis_*
#6.生成主节点的systemd启动文件
cat >/usr/lib/systemd/system/redis-master.service<<EOF
[Unit]
Description=Redis persistent key-value database
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
ExecStart=/usr/local/bin/redis-server /opt/redis_6380/conf/redis_6380.conf --supervised systemd
ExecStop=/usr/local/bin/redis-cli -h $(ifconfig eth0|awk 'NR==2{print $2}') -p 6380 shutdown
Type=notify
User=redis
Group=redis
RuntimeDirectory=redis
RuntimeDirectoryMode=0755
[Install]
WantedBy=multi-user.target
EOF
#7.复制master节点的启动文件给slave节点并修改端口号
cd /usr/lib/systemd/system/
cp redis-master.service redis-slave.service
sed -i 's#6380#6381#g' redis-slave.service
#8.重载并启动集群节点
systemctl daemon-reload
systemctl start redis-master
systemctl start redis-slave
ps -ef|grep redis
#9.把创建好的目录和启动文件发送给db02和db03
rsync -avz /opt/redis_638* 10.0.0.52:/opt/
rsync -avz /opt/redis_638* 10.0.0.53:/opt/
rsync -avz /usr/lib/systemd/system/redis-*.service 10.0.0.52:/usr/lib/systemd/system/
rsync -avz /usr/lib/systemd/system/redis-*.service 10.0.0.53:/usr/lib/systemd/system/
5.db02的操作
#1.替换db01发送过来的文件并修改IP地址
pkill redis
find /opt/redis_638* -type f -name "*.conf"|xargs sed -i "/bind/s#51#52#g"
cd /usr/lib/systemd/system/
sed -i 's#51#52#g' redis-*.service
mkdir –p /data/redis_{6380,6381}
chown -R redis:redis /opt/redis_*
chown -R redis:redis /data/redis_*
systemctl daemon-reload
systemctl start redis-master
systemctl start redis-slave
ps -ef|grep redis
6.db03的操作
#1.替换db01发送过来的文件并修改IP地址
pkill redis
find /opt/redis_638* -type f -name "*.conf"|xargs sed -i "/bind/s#51#53#g"
cd /usr/lib/systemd/system/
sed -i 's#51#53#g' redis-*.service
mkdir –p /data/redis_{6380,6381}
chown -R redis:redis /opt/redis_*
chown -R redis:redis /data/redis_*
systemctl daemon-reload
systemctl start redis-master
systemctl start redis-slave
ps -ef|grep redis
7.集群手动发现节点
redis-cli -h 10.0.0.51 -p 6380 CLUSTER MEET 10.0.0.52 6380
redis-cli -h 10.0.0.51 -p 6380 CLUSTER MEET 10.0.0.53 6380
redis-cli -h 10.0.0.51 -p 6380 CLUSTER MEET 10.0.0.51 6381
redis-cli -h 10.0.0.51 -p 6380 CLUSTER MEET 10.0.0.52 6381
redis-cli -h 10.0.0.51 -p 6380 CLUSTER MEET 10.0.0.53 6381
redis-cli -h 10.0.0.51 -p 6380 CLUSTER NODES
8.集群手动分配槽位
1.槽位规划
db01:6380 5461 0-5460
db02:6380 5461 5461-10921
db03:6380 5462 10922-16383
2.分配槽位
redis-cli -h 10.0.0.51 -p 6380 CLUSTER ADDSLOTS {0..5460}
redis-cli -h 10.0.0.52 -p 6380 CLUSTER ADDSLOTS {5461..10921}
redis-cli -h 10.0.0.53 -p 6380 CLUSTER ADDSLOTS {10922..16383}
3.查看集群状态
redis-cli -h 10.0.0.51 -p 6380 CLUSTER NODES
redis-cli -h 10.0.0.51 -p 6380 CLUSTER INFO
9.手动分配复制关系
1.先获取集群节点信息
redis-cli -h 10.0.0.52 -p 6381 CLUSTER nodes
2.过滤删除不必要的信息
6380的ID 10.0.0.51
6380的ID 10.0.0.53
6380的ID 10.0.0.52
3.画图
4.配置复制关系
redis-cli -h 10.0.0.51 -p 6381 CLUSTER REPLICATE db02的6380的ID
redis-cli -h 10.0.0.52 -p 6381 CLUSTER REPLICATE db03的6380的ID
redis-cli -h 10.0.0.53 -p 6381 CLUSTER REPLICATE db01的6380的ID
5.检查复制关系
redis-cli -h 10.0.0.51 -p 6381 CLUSTER NODES
