Redis4 Cluster部署

Redis5版本前（redis3.x及redis4.x）cluster部署较麻烦，因部署过程中涉及的依赖软件版本要求较苛刻，因此记录一下Redis4.0.14版本redis cluster的部署过程。

1 Redis各节点部署

使用源码安装各节点，不过与非cluster方式不同的是，配置文件中需启动cluster相关的配置。编译过程可参考分分钟搞定Redis编译安装

因本次为伪分布式部署，生产环境部署时建议至少3台机器部署（其中每台机器1主1从）

1.1 启动cluster各节点

创建数据目录

mkdir -p  /data/redis/cluster/{7000,7001,7002,7003,7004,7005}

配置文件中主要修改如下内容，其他的可按需调整，也可保持默认值，各节点中注意修改对应的端口号

bind 192.168.56.101
port 7000
daemonize yes
pidfile /data/redis/cluster/7000/redis_7000.pid
logfile "/data/redis/cluster/7000/redis_7000.log"
appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec
cluster-enabled yes
cluster-config-file nodes-7000.conf     #注意此文件自动生成，且初始化时不要有和此重名的文件
cluster-node-timeout 5000
cluster-slave-validity-factor 10
cluster-migration-barrier 1
cluster-require-full-coverage yes
cluster-slave-no-failover no

启动各节点，建议用redis用户启动

useradd redis
chown -R  redis:redis  /data/redis/
su - redis
cd /data/redis/cluster/7001
cp /data/redis/cluster/7000/redis.conf . 
sed -i "s#7000#7001#g" redis.conf
redis-server redis.conf

其他节点和7001类似启动，启动后进程中会标记redis节点以cluster模式启动

2. 按照依赖

因redis5之前版本前cluster安装依赖ruby，且版本要求比较苛刻，本次安装的版本redis4.0.14，依赖的ruby版本为>=ruby2.4,因此大家安装时可以安装高版本的ruby，本次我使用的是ruby2.7.5版本

2.1 编译安装ruby
下载ruby，建议从官网下载源码进行编译安装
https://www.ruby-lang.org/en/downloads/

tar -zxvf  ruby-2.7.5.tar.gz
cd ruby-2.7.5 
./configure
make  
make install

安装完毕后，检查ruby以及gem版本

2.2 安装openssl-devel及zlib-devel

安装完ruby后，使用gem安装redis包，此时如果没有安装openssl 则回报如下错误

gem install  redis
ERROR:  Loading command: install (LoadError)
    cannot load such file -- openssl
ERROR:  While executing gem ... (NoMethodError)
    undefined method `invoke_with_build_args' for nil:NilClass

按照过程如下：

yum方式先安装openssl

 yum install openssl-devel -y

再进入ruby源码目录中的ext目录下，找到openssl目录，进入后进行安装

cd ruby-2.7.5/ext/openssl
ruby extconf.rb 
make
make install

zlib-devel包如报错，也可同上方式处理。

在执行make,若出现如下报错：

 make: *** 没有规则可以创建“ossl_asn1.o”需要的目标“/include/ruby.h” 停止。

可以在Makefile顶部中的增加 top_srcdir = ../..

再次执行 make && make install

2.3 gem安装redis

 gem install redis

3. 初始化redis集群

相关依赖安装完成后，即可初始化redis集群，命令及过程如下：

[redis@localhost redis-4.0.14]$ src/redis-trib.rb create --replicas 1 192.168.56.101:7000 192.168.56.101:7001 192.168.56.101:7002 192.168.56.101:7003 192.168.56.101:7004 192.168.56.101:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.56.101:7000
192.168.56.101:7001
192.168.56.101:7002
Adding replica 192.168.56.101:7004 to 192.168.56.101:7000
Adding replica 192.168.56.101:7005 to 192.168.56.101:7001
Adding replica 192.168.56.101:7003 to 192.168.56.101:7002
>>> Trying to optimize slaves allocation for anti-affinity
[WARNING] Some slaves are in the same host as their master
M: cd6663924f0c31e6b60b815dca9cb7ea863f5573 192.168.56.101:7000
   slots:0-5460 (5461 slots) master
M: abc1f43c9a4e8813e9da15433ac66cd185dc39fe 192.168.56.101:7001
   slots:5461-10922 (5462 slots) master
M: 43fa53cec1ae164f784e5d439aaf80ee2f7e35af 192.168.56.101:7002
   slots:10923-16383 (5461 slots) master
S: 6ffcd16f1d445b0091c6239bc0988fb8a77fac96 192.168.56.101:7003
   replicates cd6663924f0c31e6b60b815dca9cb7ea863f5573
S: c523846d491f8df0bc97033b025b0d24375a13f8 192.168.56.101:7004
   replicates abc1f43c9a4e8813e9da15433ac66cd185dc39fe
S: 905dc9de7e074c282aab44b4ed5680a2020bcf4c 192.168.56.101:7005
   replicates 43fa53cec1ae164f784e5d439aaf80ee2f7e35af
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 192.168.56.101:7000)
M: cd6663924f0c31e6b60b815dca9cb7ea863f5573 192.168.56.101:7000
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
M: 43fa53cec1ae164f784e5d439aaf80ee2f7e35af 192.168.56.101:7002
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
S: c523846d491f8df0bc97033b025b0d24375a13f8 192.168.56.101:7004
   slots: (0 slots) slave
   replicates abc1f43c9a4e8813e9da15433ac66cd185dc39fe
S: 6ffcd16f1d445b0091c6239bc0988fb8a77fac96 192.168.56.101:7003
   slots: (0 slots) slave
   replicates cd6663924f0c31e6b60b815dca9cb7ea863f5573
M: abc1f43c9a4e8813e9da15433ac66cd185dc39fe 192.168.56.101:7001
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
S: 905dc9de7e074c282aab44b4ed5680a2020bcf4c 192.168.56.101:7005
   slots: (0 slots) slave
   replicates 43fa53cec1ae164f784e5d439aaf80ee2f7e35af
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

至此，redis集群初始化完毕，各节点slot范围及角色也打印出来了