redis文檔：http://doc.redisfans.com/
參考：https://www.cnblogs.com/wuxl360/p/5920330.html
http://www.cnblogs.com/carryping/p/7447823.html
https://www.jianshu.com/p/2639549bedc8
1. 下載並解壓
cd
/root/software
wget http:
//download
.redis.io
/releases/redis-3
.2.3.
tar
.gz
tar -zxvf redis-3.2.4.tar.gz 2. 編譯安裝
cd redis-3.2.3 make PREFIX=/usr/local/redis-3.2.3 install
ln -sv /usr/local/redis-3.2.3 /usr/local/redis
3. 將 redis-trib.rb 復制到 /usr/local/bin 目錄下
cd src
cp redis-trib.rb /usr/local/bin/
4. 創建 Redis 節點
首先在機器上/usr/local/redis/ 目錄下創建 cluster-test 目錄；
mkdir redis_cluster
在cluster-test 目錄下，創建名為7001、7002、7003，7004、7005、7006的目錄，並將 redis.conf 拷貝到這劉個目錄中
mkdir 7001 7002 7003 7004 7005 7006
cp redis.conf cluster-test/7001 cp redis.conf cluster-test/7002 cp redis.conf cluster-test/7003
cp redis.conf cluster-test/7004 cp redis.conf cluster-test/7005 cp redis.conf cluster-test/7006
分別修改這6個配置文件，修改如下內容
bind 0.0.0.0 port 7001 dir /usr/local/redis/cluster-test/7001 pidfile /var/run/redis_7001.pid cluster-enabled yes cluster-config-file nodes_7001.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
bind 0.0.0.0 port 7002 dir /usr/local/redis/cluster-test/7002 pidfile /var/run/redis_7002.pid cluster-enabled yes cluster-config-file nodes_7002.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
bind 0.0.0.0 port 7003 dir /usr/local/redis/cluster-test/7003 pidfile /var/run/redis_7003.pid cluster-enabled yes cluster-config-file nodes_7003.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
bind 0.0.0.0 port 7004 dir /usr/local/redis/cluster-test/7004 pidfile /var/run/redis_7004.pid cluster-enabled yes cluster-config-file nodes_7004.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
bind 0.0.0.0 port 7005 dir /usr/local/redis/cluster-test/7005 pidfile /var/run/redis_7005.pid cluster-enabled yes cluster-config-file nodes_7005.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
pidfile /var/run/redis_7006.pid cluster-enabled yes cluster-config-file nodes_7006.conf cluster-node-timeout 15000 appendonly yes appendfilename "appendonly.aof" daemonize yes protected-mode yes tcp-backlog 511 timeout 0 tcp-keepalive 300 supervised no loglevel verbose logfile "" databases 16 save 900 1 save 300 10 save 60 10000 stop-writes-on-bgsave-error yes rdbcompression yes rdbchecksum yes 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 appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb 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 client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
port 7001 //端口7001,7002,7001 bind 本機ip //默認ip為127.0.0.1 需要改為其他節點機器可訪問的ip 否則創建集群時無法訪問對應的端口，無法創建集群 daemonize yes //redis后台運行 pidfile /var/run/redis_7001.pid //pidfile文件對應7001,7002,7003 cluster-enabled yes //開啟集群 把注釋#去掉 cluster-config-file nodes_7001.conf //集群的配置 配置文件首次啟動自動生成 7001,7002,7003 cluster-node-timeout 15000 //請求超時 默認15秒，可自行設置 appendonly yes //aof日志開啟 有需要就開啟，它會每次寫操作都記錄一條日志
5.啟動並查看
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7001/redis.conf /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7002/redis.conf /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7003/redis.conf /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7004/redis.conf /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7005/redis.conf /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7006/redis.conf
查看顯示下面信息
[root@localhost 7001]# netstat -ntlp |grep redis
tcp 0 0 0.0.0.0:7005 0.0.0.0:* LISTEN 19225/redis-server
tcp 0 0 0.0.0.0:7006 0.0.0.0:* LISTEN 19229/redis-server
tcp 0 0 0.0.0.0:17001 0.0.0.0:* LISTEN 19209/redis-server
tcp 0 0 0.0.0.0:17002 0.0.0.0:* LISTEN 19213/redis-server
tcp 0 0 0.0.0.0:17003 0.0.0.0:* LISTEN 19215/redis-server
tcp 0 0 0.0.0.0:17004 0.0.0.0:* LISTEN 19221/redis-server
tcp 0 0 0.0.0.0:17005 0.0.0.0:* LISTEN 19225/redis-server
tcp 0 0 0.0.0.0:17006 0.0.0.0:* LISTEN 19229/redis-server
tcp 0 0 0.0.0.0:7001 0.0.0.0:* LISTEN 19209/redis-server
tcp 0 0 0.0.0.0:7002 0.0.0.0:* LISTEN 19213/redis-server
tcp 0 0 0.0.0.0:7003 0.0.0.0:* LISTEN 19215/redis-server
tcp 0 0 0.0.0.0:7004 0.0.0.0:* LISTEN 19221/redis-server
6.創建集群
redis-trib.rb create --replicas 1 192.168.8.102:7001 192.168.8.102:7002 192.168.8.102:7003 192.168.8.102:7004 192.168.8.102:7005 192.168.8.102:7006
gem install redis 報錯
ERROR: Error installing redis:
redis requires Ruby version >= 2.2.2.
解決辦法是 先安裝rvm，再把ruby版本提升至2.4.5
1.安裝curl
sudo yum install curl
2. 安裝RVM
curl -L get.rvm.io | bash -s stable
再次報錯：
[root@localhost yum.repos.d]# curl -L get.rvm.io | bash -s stable
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 24173 100 24173 0 0 21587 0 0:00:01 0:00:01 --:--:-- 128k
Downloading https://github.com/rvm/rvm/archive/1.29.7.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.7/1.29.7.tar.gz.asc
gpg: Signature made Fri 04 Jan 2019 06:01:48 AM CST using RSA key ID 39499BDB
gpg: Can't check signature: No public key
GPG signature verification failed for '/usr/local/rvm/archives/rvm-1.29.7.tgz' - 'https://github.com/rvm/rvm/releases/download/1.29.7/1.29.7.tar.gz.asc'! Try to install GPG v2 and then fetch the public key:
gpg2 --keyserver hkp://pool.sks-keyservers.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
or if it fails:
command curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
command curl -sSL https://rvm.io/pkuczynski.asc | gpg2 --import -
In case of further problems with validation please refer to https://rvm.io/rvm/security
那就按照上面的執行上面語句就OK啦
3.
source /usr/local/rvm/scripts/rvm
4. 查看rvm庫中已知的ruby版本
rvm list known
5. 安裝一個ruby版本
rvm install 2.4.5
6. 使用一個ruby版本
rvm use 2.4.5
7. 卸載一個已知版本
rvm remove 2.0.0
8. 查看版本
ruby --version
9. 再安裝redis就可以了
gem install redis
再執行 輸入 yes 即可，然后出現如下內容，說明安裝成功：
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.8.102:7001
192.168.8.102:7002
192.168.8.102:7003
Adding replica 192.168.8.102:7004 to 192.168.8.102:7001
Adding replica 192.168.8.102:7005 to 192.168.8.102:7002
Adding replica 192.168.8.102:7006 to 192.168.8.102:7003
M: 229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001
slots:0-5460 (5461 slots) master
M: ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002
slots:5461-10922 (5462 slots) master
M: 1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003
slots:10923-16383 (5461 slots) master
S: 837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004
replicates 229393055278b1cded847e554739255905b33fb3
S: 0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005
replicates ef175d84db52e084b5d74cf9f1c414011bf6cce9
S: b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006
replicates 1bca1b7b96f3fe936ad44f254d17da26da9fd186
Can I set the above configuration? (type 'yes' to accept): yes
>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
Waiting for the cluster to join....
>>> Performing Cluster Check (using node 192.168.8.102:7001)
M: 229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001
slots:0-5460 (5461 slots) master
1 additional replica(s)
M: 1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003
slots:10923-16383 (5461 slots) master
1 additional replica(s)
M: ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005
slots: (0 slots) slave
replicates ef175d84db52e084b5d74cf9f1c414011bf6cce9
S: 837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004
slots: (0 slots) slave
replicates 229393055278b1cded847e554739255905b33fb3
S: b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006
slots: (0 slots) slave
replicates 1bca1b7b96f3fe936ad44f254d17da26da9fd186
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
7.測試
[root@localhost 7001]# ../../bin/redis-cli -c -h 192.168.8.102 -p 7001 192.168.8.102:7001> 192.168.8.102:7001> 192.168.8.102:7001> set name zhangsan -> Redirected to slot [5798] located at 192.168.8.102:7002 OK [root@localhost 7001]# ../../../redis/bin/redis-cli -c -p 7006 127.0.0.1:7006> 127.0.0.1:7006> 127.0.0.1:7006> 127.0.0.1:7006> get name -> Redirected to slot [5798] located at 192.168.8.102:7002 "zhangsan"
驗證數據一致性
[root@localhost 7003]# md5sum dump.rdb
2604704e38811948117ddc473d62dc55 dump.rdb
[root@localhost 7001]# md5sum dump.rdb
2604704e38811948117ddc473d62dc55 dump.rdb
說明集群運作正常。
8.測試故障
讓192.168.8.102:7003當掉
[root@localhost 7001]# cat nodes_7001.conf 1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003 master - 0 1551780190387 3 connected 10923-16383 ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551780191393 2 connected 5461-10922 0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551780188372 5 connected 229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460 837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551780187366 4 connected b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006 slave 1bca1b7b96f3fe936ad44f254d17da26da9fd186 0 1551780189379 6 connected
[root@localhost 7001]# netstat -ntlp |grep 7003
tcp 0 0 0.0.0.0:17003 0.0.0.0:* LISTEN 19215/redis-server
tcp 0 0 0.0.0.0:7003 0.0.0.0:* LISTEN 19215/redis-server
[root@localhost 7001]#
[root@localhost 7001]#
[root@localhost 7001]#
[root@localhost 7001]#
[root@localhost 7001]# kill -9 19215
[root@localhost 7001]#
[root@localhost 7001]# cat nodes_7001.conf
1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003 master,fail - 1551784667064 1551784663541 3 disconnected
ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551784682702 2 connected 5461-10922
0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551784681691 5 connected
229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460
837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551784679675 4 connected
b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006 master - 0 1551784680684 7 connected 10923-16383
vars currentEpoch 7 lastVoteEpoch 7
[root@localhost 7001]# redis-cli -c -p 7001
127.0.0.1:7001>
127.0.0.1:7001>
127.0.0.1:7001>
127.0.0.1:7001> get name
-> Redirected to slot [5798] located at 192.168.8.102:7002
"zhangsan"
可以訪問
再當掉192.168.8.102:7006
[root@localhost 7001]# redis-cli -c -p 7001
127.0.0.1:7001>
127.0.0.1:7001>
127.0.0.1:7001>
127.0.0.1:7001> get name
(error) CLUSTERDOWN The cluster is down
127.0.0.1:7001>
[root@localhost 7001]# !cat
cat nodes_7001.conf
1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003 slave,fail b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 1551785439155 1551785434725 7 disconnected
ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551785536517 2 connected 5461-10922
0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551785537528 5 connected
229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460
837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551785539547 4 connected
b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 :0 master,fail,noaddr - 1551785518472 1551785516358 7 disconnected 10923-16383
vars currentEpoch 7 lastVoteEpoch 7
開啟主節點：7006端口
[root@localhost 7001]# cat ../start_cluster.sh
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7001/redis.conf
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7002/redis.conf
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7003/redis.conf
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7004/redis.conf
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7005/redis.conf
/usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7006/redis.conf
[root@localhost 7001]#
[root@localhost 7001]#
[root@localhost 7001]# /usr/local/redis/bin/redis-server /usr/local/redis/cluster-test/7006/redis.conf
[root@localhost 7001]#
[root@localhost 7001]# cat nodes_7001.conf
1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003 slave,fail b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 0 1551785119857 7 connected
ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551785118344 2 connected 5461-10922
0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551785119352 5 connected
229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460
837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551785117336 4 connected
b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006 master - 0 1551785786843 7 connected 10923-16383
再檢測又可以訪問了
[root@localhost 7001]# redis-cli -c -p 7001
127.0.0.1:7001>
127.0.0.1:7001>
127.0.0.1:7001> get name
-> Redirected to slot [5798] located at 192.168.8.102:7002
"zhangsan"
注意：恢復時，先恢復主節點 再恢復從節點
簡單說一下原理
redis cluster在設計的時候，就考慮到了去中心化，去中間件，也就是說，集群中的每個節點都是平等的關系，都是對等的，每個節點都保存各自的數據和整個集群的狀態。每個節點都和其他所有節點連接，而且這些連接保持活躍，這樣就保證了我們只需要連接集群中的任意一個節點，就可以獲取到其他節點的數據。
Redis 集群沒有並使用傳統的一致性哈希來分配數據，而是采用另外一種叫做哈希槽 (hash slot)的方式來分配的。redis cluster 默認分配了 16384 個slot，當我們set一個key 時，會用CRC16算法來取模得到所屬的slot，然后將這個key 分到哈希槽區間的節點上，具體算法就是：CRC16(key) % 16384。所以我們在測試的時候看到set 和 get 的時候，直接跳轉到了7000端口的節點。
Redis 集群會把數據存在一個 master 節點，然后在這個 master 和其對應的salve 之間進行數據同步。當讀取數據時，也根據一致性哈希算法到對應的 master 節點獲取數據。只有當一個master 掛掉之后，才會啟動一個對應的 salve 節點，充當 master 。
需要注意的是：必須要3個或以上的主節點，否則在創建集群時會失敗，並且當存活的主節點數小於總節點數的一半時，整個集群就無法提供服務了。