《Redis专题》-Redis-culster集群搭建

2023-08-18 08:25:22

文章目录

1.Redis-cluster架构图

架构细节:

(1)所有的redis节点彼此互联(PING-PONG机制),内部使用二进制协议优化传输速度和带宽.

(2)节点的fail是通过集群中超过半数的节点检测失效时才生效.

(3)客户端与redis节点直连,不需要中间proxy层.客户端不需要连接集群所有节点,连接集群中任何一个可用节点即可

(4) redis-cluster把所有的物理节点映射到[0-16383]slot槽上,cluster 负责维护node<->slot<->value
Redis 集群中内置了 16384 个哈希槽，当需要在 Redis 集群中放置一个 key-value 时，redis 先对 key 使用 crc16 算法算出一个结果，然后把结果对 16384 求余数，这样每个 key 都会对应一个编号在 0-16383 之间的哈希槽，redis 会根据节点数量大致均等的将哈希槽映射到不同的节点！

示例如下：

2.Redis-cluster投票:容错

(1)集群中所有master参与投票,如果半数以上master节点与其中一个master节点通信超过(cluster-node-timeout),认为该master节点挂掉.

(2):什么时候整个集群不可用(cluster_state:fail)?
 如果集群任意master挂掉,且当前master没有slave，则集群进入fail状态。也可以理解成集群的[0-16383]slot映射不完全时进入fail状态。
 如果集群超过半数以上master挂掉，无论是否有slave，集群进入fail状态。

3.Redis-cluster集群搭建环境准备

集群管理工具（redis-trib.rb）是使用ruby脚本语言编写的。

第一步: 安装ruby

[root@redis1 bin]# yum install ruby
[root@redis1 bin]# yum install rubygems

第二步：将以下文件上传到linux系统

第三步：安装ruby和redis接口

-rw-r--r--. 1 root root 22301 8月  18 2016 dangdang.sql
drwxr-xr-x. 3 root root  4096 7月   1 10:00 redis
drwxr-xr-x. 3 root root  4096 7月   1 09:54 redis1
drwxrwxr-x. 6 root root  4096 4月   1 2015 redis-3.0.0
-rw-r--r--. 1 root root 57856 7月   1 10:03 redis-3.0.0.gem
drwxr-xr-x. 9 root root  4096 6月  28 23:26 tomcat
[root@bruce1 myapps]# gem install redis-3.0.0.gem

第四步：将redis-3.0.0包下src目录中的以下文件拷贝到redis-cluster/

[root@bruce1 myapps]# mkdir redis-cluster
[root@bruce1 myapps]# cd redis-3.0.0/src/
[root@bruce1 src]# cp redis-trib.rb ~/myapps/redis-cluster/
[root@bruce1 src]# ll ~/myapps/redis-cluster/
总用量 48
-rwxr-xr-x. 1 root root 48141 7月   1 10:20 redis-trib.rb

4.Redis-cluster集群搭建过程

搭建集群最少也得需要3台主机，如果每台主机再配置一台从机的话，则最少需要6台机器。
设计端口如下：创建6个redis实例，需要端口号7001~7006 伪集群

第一步：复制出一个7001实例

[root@bruce1 myapps]# cp redis/ redis-cluster/7001 -r 
[root@bruce1 myapps]# cd redis-cluster/7001
[root@bruce1 7001]# ll
总用量 52
drwxr-xr-x. 2 root root  4096 7月   1 10:22 bin
-rw-r--r--. 1 root root  3446 7月   1 10:22 dump.rdb
-rw-r--r--. 1 root root 41404 7月   1 10:22 redis.conf

第二步：如果存在持久化文件，则删除

[root@bruce1 bin]# rm -rf appendonly.aof dump.rdb

第三步：修改redis.conf配置文件，打开cluster-enable yes

第四步：修改端口

第五步：复制出7002-7006机器

[root@bruce1 redis-cluster]# cp 7001/ 7002 -r
[root@bruce1 redis-cluster]# cp 7001/ 7003 -r
[root@bruce1 redis-cluster]# cp 7001/ 7004 -r
[root@bruce1 redis-cluster]# cp 7001/ 7005 -r
[root@bruce1 redis-cluster]# cp 7001/ 7006 –r

第六步：修改7002-7006机器的端口
第七步：启动7001-7006这六台机器，写一个启动脚本

cd 7001
./bin/redis-server ./redis.conf
cd ..
cd 7002
./bin/redis-server ./redis.conf 
cd ..
cd 7003
./bin/redis-server ./redis.conf
cd ..
cd 7004
./bin/redis-server ./redis.conf
cd ..
cd 7005
./bin/redis-server ./redis.conf
cd ..
cd 7006
./bin/redis-server ./redis.conf
cd ..

第八步：修改start-all.sh文件的权限

[root@bruce1 redis-cluster]# chmod u+x start-all.sh

第九步：启动所有的实例

[root@bruce1 redis-cluster]# ./start-all.sh

第十步：创建集群

[root@bruce1 redis-cluster]# ./redis-trib.rb create --replicas 1 192.168.221.128:7001 192.168.221.128:7002 192.168.221.128:7003 192.168.221.128:7004 192.168.221.128:7005  192.168.221.128:7006
>>> Creating cluster
Connecting to node 192.168.221.128:7001: OK
Connecting to node 192.168.221.128:7002: OK
Connecting to node 192.168.221.128:7003: OK
Connecting to node 192.168.221.128:7004: OK
Connecting to node 192.168.221.128:7005: OK
Connecting to node 192.168.221.128:7006: OK
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.221.128:7001
192.168.221.128:7002
192.168.221.128:7003
Adding replica 192.168.221.128:7004 to 192.168.221.128:7001
Adding replica 192.168.221.128:7005 to 192.168.221.128:7002
Adding replica 192.168.221.128:7006 to 192.168.221.128:7003
M: e7fb45e74f828b53ccd8b335f3ed587aa115b903 192.168.221.128:7001
   slots:0-5460 (5461 slots) master
M: 4a312b6fc90bfee187d43588ead99d83b407c892 192.168.221.128:7002
   slots:5461-10922 (5462 slots) master
M: 713218b88321e5067fd8ad25c3bf7db88c878ccf 192.168.221.128:7003
   slots:10923-16383 (5461 slots) master
S: 4f8c7455574e2f0aab1e2bb341eae319ac065039 192.168.221.128:7004
   replicates e7fb45e74f828b53ccd8b335f3ed587aa115b903
S: 8879c2ed9c141de70cb7d5fcb7d690ed8a200792 192.168.221.128:7005
   replicates 4a312b6fc90bfee187d43588ead99d83b407c892
S: b1183545245b3a710a95d669d7bbcbb5e09896a0 192.168.221.128:7006
   replicates 713218b88321e5067fd8ad25c3bf7db88c878ccf
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 192.168.221.128:7001)
M: e7fb45e74f828b53ccd8b335f3ed587aa115b903 192.168.221.128:7001
   slots:0-5460 (5461 slots) master
M: 4a312b6fc90bfee187d43588ead99d83b407c892 192.168.221.128:7002
   slots:5461-10922 (5462 slots) master
M: 713218b88321e5067fd8ad25c3bf7db88c878ccf 192.168.221.128:7003
   slots:10923-16383 (5461 slots) master
M: 4f8c7455574e2f0aab1e2bb341eae319ac065039 192.168.221.128:7004
   slots: (0 slots) master
   replicates e7fb45e74f828b53ccd8b335f3ed587aa115b903
M: 8879c2ed9c141de70cb7d5fcb7d690ed8a200792 192.168.221.128:7005
   slots: (0 slots) master
   replicates 4a312b6fc90bfee187d43588ead99d83b407c892
M: b1183545245b3a710a95d669d7bbcbb5e09896a0 192.168.221.128:7006
   slots: (0 slots) master
   replicates 713218b88321e5067fd8ad25c3bf7db88c878ccf
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

5.Redis-cluster集群连接

命令: [root@bruce1 7001]# ./bin/redis-cli -h 192.168.221.128 -p 7001 -c
-c：指定是集群连接

[root@bruce1 7001]# ./bin/redis-cli -h 192.168.221.128 -p 7001 -c
192.168.221.128:7001> set username bruceliu123
-> Redirected to slot [14315] located at 192.168.221.128:7003
OK

6.查看集群信息

192.168.221.128:7003> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:6
cluster_my_epoch:3
cluster_stats_messages_sent:1186
cluster_stats_messages_received:1186

7.查看集群信息

192.168.221.128:7003> cluster nodes
713218b88321e5067fd8ad25c3bf7db88c878ccf 192.168.221.128:7003 myself,master - 0 0 3 connected 10923-16383
e7fb45e74f828b53ccd8b335f3ed587aa115b903 192.168.221.128:7001 master - 0 1498877677276 1 connected 0-5460
b1183545245b3a710a95d669d7bbcbb5e09896a0 192.168.221.128:7006 slave 713218b88321e5067fd8ad25c3bf7db88c878ccf 0 1498877679294 3 connected
8879c2ed9c141de70cb7d5fcb7d690ed8a200792 192.168.221.128:7005 slave 4a312b6fc90bfee187d43588ead99d83b407c892 0 1498877678285 5 connected
4a312b6fc90bfee187d43588ead99d83b407c892 192.168.221.128:7002 master - 0 1498877674248 2 connected 5461-10922
4f8c7455574e2f0aab1e2bb341eae319ac065039 192.168.221.128:7004 slave e7fb45e74f828b53ccd8b335f3ed587aa115b903 0 1498877680308 4 connected

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