Redis redis-trib集群配置

it2022-05-07  0

 

redis文档:http://doc.redisfans.com/

参考:https://www.cnblogs.com/wuxl360/p/5920330.html

          http://www.cnblogs.com/carryping/p/7447823.html

         https://www.jianshu.com/p/2639549bedc8

 

1. 下载并解压

cd /root/software wget http: //download .redis.io /releases/redis-3 .2.3. tar .gz tar -zxvf redis-3.2.4.tar.gz 

2. 编译安装

cd redis-3.2.3 make PREFIX=/usr/local/redis-3.2.3 installln -sv /usr/local/redis-3.2.3 /usr/local/redis

3. 将 redis-trib.rb 复制到 /usr/local/bin 目录下

cd src cp redis-trib.rb /usr/local/bin/  

4. 创建 Redis 节点

首先在机器上/usr/local/redis/ 目录下创建 cluster-test 目录;

mkdir redis_cluster  

在cluster-test 目录下,创建名为7001、7002、7003,7004、7005、7006的目录,并将 redis.conf 拷贝到这刘个目录中

mkdir 7001 7002 7003 7004 7005 7006cp redis.conf cluster-test/7001 cp redis.conf cluster-test/7002 cp redis.conf cluster-test/7003cp redis.conf cluster-test/7004 cp redis.conf cluster-test/7005 cp redis.conf cluster-test/7006    

分别修改这6个配置文件,修改如下内容

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 7001 redis.conf 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 7002 redis.conf 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 7003 redis.conf 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 7004 redis.conf 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 7005 redis.conf 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 7006 redis.conf port 7001 //端口7001,7002,7001 bind 本机ip //默认ip为127.0.0.1 需要改为其他节点机器可访问的ip 否则创建集群时无法访问对应的端口,无法创建集群 daemonize yes //redis后台运行 pidfile /var/run/redis_7001.pid //pidfile文件对应7001,7002,7003 cluster-enabled yes //开启集群 把注释#去掉 cluster-config-file nodes_7001.conf //集群的配置 配置文件首次启动自动生成 7001,7002,7003 cluster-node-timeout 15000 //请求超时 默认15秒,可自行设置 appendonly yes //aof日志开启 有需要就开启,它会每次写操作都记录一条日志 

5.启动并查看

/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查看显示下面信息[root@localhost 7001]# netstat -ntlp |grep redistcp        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.创建集群

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 报错 ERROR: Error installing redis: redis requires Ruby version >= 2.2.2.解决办法是 先安装rvm,再把ruby版本提升至2.4.51.安装curlsudo yum install curl2. 安装RVMcurl -L get.rvm.io | bash -s stable 再次报错:[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  Speed100 24173  100 24173    0     0  21587      0  0:00:01  0:00:01 --:--:--  128kDownloading https://github.com/rvm/rvm/archive/1.29.7.tar.gzDownloading https://github.com/rvm/rvm/releases/download/1.29.7/1.29.7.tar.gz.ascgpg: Signature made Fri 04 Jan 2019 06:01:48 AM CST using RSA key ID 39499BDBgpg: Can't check signature: No public keyGPG 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 7D2BAF1CF37B13E2069D6956105BD0E739499BDBor 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那就按照上面的执行上面语句就OK啦3. source /usr/local/rvm/scripts/rvm4. 查看rvm库中已知的ruby版本rvm list known5. 安装一个ruby版本rvm install 2.4.56. 使用一个ruby版本rvm use 2.4.57. 卸载一个已知版本rvm remove 2.0.08. 查看版本ruby --version9. 再安装redis就可以了gem install redis再执行 输入 yes 即可,然后出现如下内容,说明安装成功:>>> Creating cluster>>> Performing hash slots allocation on 6 nodes...Using 3 masters:192.168.8.102:7001192.168.8.102:7002192.168.8.102:7003Adding replica 192.168.8.102:7004 to 192.168.8.102:7001Adding replica 192.168.8.102:7005 to 192.168.8.102:7002Adding replica 192.168.8.102:7006 to 192.168.8.102:7003M: 229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001   slots:0-5460 (5461 slots) masterM: ef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002   slots:5461-10922 (5462 slots) masterM: 1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003   slots:10923-16383 (5461 slots) masterS: 837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004   replicates 229393055278b1cded847e554739255905b33fb3S: 0f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005   replicates ef175d84db52e084b5d74cf9f1c414011bf6cce9S: b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006   replicates 1bca1b7b96f3fe936ad44f254d17da26da9fd186Can 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 clusterWaiting 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 ef175d84db52e084b5d74cf9f1c414011bf6cce9S: 837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004   slots: (0 slots) slave   replicates 229393055278b1cded847e554739255905b33fb3S: 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.测试

[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"验证数据一致性[root@localhost 7003]# md5sum dump.rdb 2604704e38811948117ddc473d62dc55  dump.rdb[root@localhost 7001]# md5sum dump.rdb 2604704e38811948117ddc473d62dc55  dump.rdb 说明集群运作正常。

 

8.测试故障

让192.168.8.102:7003当掉[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 7003tcp        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 disconnectedef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551784682702 2 connected 5461-109220f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551784681691 5 connected229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551784679675 4 connectedb41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006 master - 0 1551784680684 7 connected 10923-16383vars currentEpoch 7 lastVoteEpoch 7[root@localhost 7001]# redis-cli -c -p 7001127.0.0.1:7001> 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"可以访问再当掉192.168.8.102:7006[root@localhost 7001]# redis-cli -c -p 7001127.0.0.1:7001> 127.0.0.1:7001> 127.0.0.1:7001> 127.0.0.1:7001> get name(error) CLUSTERDOWN The cluster is down127.0.0.1:7001> [root@localhost 7001]# !catcat nodes_7001.conf 1bca1b7b96f3fe936ad44f254d17da26da9fd186 192.168.8.102:7003 slave,fail b41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 1551785439155 1551785434725 7 disconnectedef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551785536517 2 connected 5461-109220f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551785537528 5 connected229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551785539547 4 connectedb41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 :0 master,fail,noaddr - 1551785518472 1551785516358 7 disconnected 10923-16383vars currentEpoch 7 lastVoteEpoch 7开启主节点: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 connectedef175d84db52e084b5d74cf9f1c414011bf6cce9 192.168.8.102:7002 master - 0 1551785118344 2 connected 5461-109220f3d5f7e78dc857efc5b58ab674faee9fba876af 192.168.8.102:7005 slave ef175d84db52e084b5d74cf9f1c414011bf6cce9 0 1551785119352 5 connected229393055278b1cded847e554739255905b33fb3 192.168.8.102:7001 myself,master - 0 0 1 connected 0-5460837eea90f07c9cdebfa7e1924d2e2788cf5573eb 192.168.8.102:7004 slave 229393055278b1cded847e554739255905b33fb3 0 1551785117336 4 connectedb41ae432b4bd8d7ca44bf318c7b9382f8dbd7a79 192.168.8.102:7006 master - 0 1551785786843 7 connected 10923-16383再检测又可以访问了[root@localhost 7001]# redis-cli -c -p 7001127.0.0.1:7001> 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:恢复时,先恢复主节点 再恢复从节点

 

简单说一下原理

redis cluster在设计的时候,就考虑到了去中心化,去中间件,也就是说,集群中的每个节点都是平等的关系,都是对等的,每个节点都保存各自的数据和整个集群的状态。每个节点都和其他所有节点连接,而且这些连接保持活跃,这样就保证了我们只需要连接集群中的任意一个节点,就可以获取到其他节点的数据。

Redis 集群没有并使用传统的一致性哈希来分配数据,而是采用另外一种叫做哈希槽 (hash slot)的方式来分配的。redis cluster 默认分配了 16384 个slot,当我们set一个key 时,会用CRC16算法来取模得到所属的slot,然后将这个key 分到哈希槽区间的节点上,具体算法就是:CRC16(key) % 16384。所以我们在测试的时候看到set 和 get 的时候,直接跳转到了7000端口的节点。

Redis 集群会把数据存在一个 master 节点,然后在这个 master 和其对应的salve 之间进行数据同步。当读取数据时,也根据一致性哈希算法到对应的 master 节点获取数据。只有当一个master 挂掉之后,才会启动一个对应的 salve 节点,充当 master 。

需要注意的是:必须要3个或以上的主节点,否则在创建集群时会失败,并且当存活的主节点数小于总节点数的一半时,整个集群就无法提供服务了。

转载于:https://www.cnblogs.com/icemonkey/p/10478751.html

相关资源:docker 运行redis-trib 带密码创建redis cluster集群配置

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