一、本文目标
要在单台机器上搭建Redis集群，方式是通过不同的TCP端口启动多个实例，然后组成集群，同时记录在搭建过程中踩过的坑。
二、安装准备
centos版本：6.7
redis版本：3.2.3
安装方式：源码安装
服务器：1台
三、操作步骤
此处默认已安装好单台redis
1、启动Redis多个实例
我们在Redis安装目录下创建目录cluster，并编写7000.conf~7005.conf 6个配置文件，这6个配置文件用来启动6个实例，后面将使用这6个实例组成集群。
以7000.conf为例，配置文件需要填写如下几项：
port 7000 //端口7000,7001,7002,7003,7004,7005
bind 192.168.186.91 //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 ./redis_7000.pid //pidfile文件对应7000,7001,7002,7003,7004,7005
cluster-enabled yes //开启集群 把注释#去掉
cluster-config-file nodes_7000.conf //集群的配置 配置文件首次启动自动生成 7000,7001,7002,7003,7004,7005
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
分别启动6个实例
redis-server redis_cluster/7000/redis.conf
redis-server redis_cluster/7001/redis.conf
redis-server redis_cluster/7002/redis.conf
redis-server redis_cluster/7003/redis.conf
redis-server redis_cluster/7004/redis.conf
redis-server redis_cluster/7005/redis.conf
启动成功后，看一下进程
# ps -ef | grep redis | grep cluster
idata 15711 22329 0 18:40 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7000 [cluster]
idata 15740 22329 0 18:40 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7001 [cluster]
idata 15810 22329 0 18:40 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7002 [cluster]
idata 17023 22329 0 18:42 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7003 [cluster]
idata 17030 22329 0 18:42 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7004 [cluster]
idata 17035 22329 0 18:42 pts/10 00:00:00 ./bin/redis-server 192.168.186.91:7005 [cluster]
至此，ip=192.168.186.91机器上创建了6个实例，端口号为port=7000~7005。
2、安装ruby
1）yum安装ruby和依赖的包。
[root@itfirst redis_cluster]# yum -y install ruby ruby-devel rubygems rpm-build
2）使用gem这个命令来安装redis接口
[root@itfirst redis_cluster]# gem install redis
ERROR: Error installing redis:
redis requires Ruby version >= 2.2.2.
这一步骤中出现了bug,度娘告诉我是Ruby版本太低，需要升级版本。
3）升级Ruby的版本
安装rvm，我不知道这是个什么东西，但是感觉像是Ruby的一个包管理器。
[root@itfirst redis_cluster]# curl -L get.rvm.io | bash -s stable
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 24090 100 24090 0 0 10919 0 0:00:02 0:00:02 --:--:-- 91242
Downloading https://github.com/rvm/rvm/archive/1.29.3.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.3/1.29.3.tar.gz.asc
gpg: 于 2017年09月11日 星期一 04时59分21秒 CST 创建的签名，使用 RSA，钥匙号 BF04FF17
gpg: 无法检查签名：No public key
Warning, RVM 1.26.0 introduces signed releases and automated check of signatures when GPG software found.Assuming you trust Michal Papis import the mpapis public key (downloading the signatures).
GPG signature verification failed for '/usr/local/rvm/archives/rvm-1.29.3.tgz' -'https://github.com/rvm/rvm/releases/download/1.29.3/1.29.3.tar.gz.asc'! Try to install GPG v2 and then fetch the publickey:
gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
or if it fails:
command curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
the key can be compared with:
NOTE: GPG version 2.1.17 have a bug which cause failures during fetching keys from remote server. Please downgradeor upgrade to newer version (if available) or use the second method described above.
这一操作得到了：
gpg2 –recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
然后利用该密钥下载Ruby并升级。
[root@itfirst redis_cluster]# gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
gpg: 下载密钥‘D39DC0E3’，从 hkp 服务器 keys.gnupg.net
gpg: /root/.gnupg/trustdb.gpg：建立了信任度数据库
gpg: 密钥 D39DC0E3：公钥“Michal Papis (RVM signing) <mpapis@gmail.com>”已导入
gpg: 没有找到任何绝对信任的密钥
gpg: 合计被处理的数量：1
gpg: 已导入：1 (RSA: 1)
[root@itfirst redis_cluster]# curl -sSL https://get.rvm.io | bash -s stable
Downloading https://github.com/rvm/rvm/archive/1.29.3.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.3/1.29.3.tar.gz.asc
gpg: 于 2017年09月11日 星期一 04时59分21秒 CST 创建的签名，使用 RSA，钥匙号 BF04FF17
gpg: 完好的签名，来自于“Michal Papis (RVM signing) <mpapis@gmail.com>”
gpg: 亦即“Michal Papis <mpapis@gmail.com>”
gpg: 亦即“[jpeg image of size 5015]”
gpg: 警告：这把密钥未经受信任的签名认证！
gpg: 没有证据表明这个签名属于它所声称的持有者。
主钥指纹： 409B 6B17 96C2 7546 2A17 0311 3804 BB82 D39D C0E3
子钥指纹： 62C9 E5F4 DA30 0D94 AC36 166B E206 C29F BF04 FF17
GPG verified '/usr/local/rvm/archives/rvm-1.29.3.tgz'
Creating group 'rvm'
Installing RVM to /usr/local/rvm/
Installation of RVM in /usr/local/rvm/ is almost complete:
* First you need to add all users that will be using rvm to 'rvm' group,
and logout - login again, anyone using rvm will be operating with `umask u=rwx,g=rwx,o=rx`.
* To start using RVM you need to run `source /etc/profile.d/rvm.sh`
in all your open shell windows, in rare cases you need to reopen all shell windows.
接着，source环境，让rvm可用。
[root@itfirst ~]# source /usr/local/rvm/scripts/rvm
查看Ruby可用版本
[root@itfirst ~]# rvm list known
# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10]
[ruby-]2.2[.7]
[ruby-]2.3[.4]
[ruby-]2.4[.1]
ruby-head
# for forks use: rvm install ruby-head-<name> --url https://github.com/github/ruby.git --branch 2.2
# JRuby
jruby-1.6[.8]
jruby-1.7[.27]
jruby[-9.1.13.0]
jruby-head
# Rubinius
rbx-1[.4.3]
rbx-2.3[.0]
rbx-2.4[.1]
rbx-2[.5.8]
rbx-3[.84]
rbx-head
# Opal
opal
# Minimalistic ruby implementation - ISO 30170:2012
mruby-1.0.0
mruby-1.1.0
mruby-1.2.0
mruby-1[.3.0]
mruby[-head]
# Ruby Enterprise Edition
ree-1.8.6
ree[-1.8.7][-2012.02]
# Topaz
topaz
# MagLev
maglev[-head]
maglev-1.0.0
# Mac OS X Snow Leopard Or Newer
macruby-0.10
macruby-0.11
macruby[-0.12]
macruby-nightly
macruby-head
# IronRuby
ironruby[-1.1.3]
ironruby-head
可以看到最新的版本是2.4.1，本文安装2.3.0
至此，我们升级了Ruby的版本。
[root@itfirst ~]# rvm install 2.3.0
Searching for binary rubies, this might take some time.
Found remote file https://rvm_io.global.ssl.fastly.net/binaries/centos/6/x86_64/ruby-2.3.0.tar.bz2
Checking requirements for centos.
Installing requirements for centos.
Installing required packages: autoconf, automake, bison, libffi-devel, libtool, readline-devel, sqlite-devel, libyaml-devel..........
Requirements installation successful.
ruby-2.3.0 - #configure
ruby-2.3.0 - #download
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 21.9M 100 21.9M 0 0 266k 0 0:01:24 0:01:24 --:--:-- 278k
No checksum for downloaded archive, recording checksum in user configuration.
ruby-2.3.0 - #validate archive
ruby-2.3.0 - #extract
ruby-2.3.0 - #validate binary
ruby-2.3.0 - #setup
ruby-2.3.0 - #gemset created /usr/local/rvm/gems/ruby-2.3.0@global
ruby-2.3.0 - #importing gemset /usr/local/rvm/gemsets/global.gems..............................
ruby-2.3.0 - #generating global wrappers........
ruby-2.3.0 - #gemset created /usr/local/rvm/gems/ruby-2.3.0
ruby-2.3.0 - #importing gemsetfile /usr/local/rvm/gemsets/default.gems evaluated to empty gem list
ruby-2.3.0 - #generating default wrappers........
4）安装gem redis接口
[root@itfirst ~]# rvm use 2.3.0
Using /usr/local/rvm/gems/ruby-2.3.0
[root@itfirst ~]# rvm remove 1.8.7
ruby-1.8.7-head - #already gone
Using /usr/local/rvm/gems/ruby-2.3.0
[root@itfirst ~]# ruby --version
ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-linux]
[root@itfirst ~]# gem install redis
Fetching: redis-4.0.1.gem (100%)
Successfully installed redis-4.0.1
Parsing documentation for redis-4.0.1
Installing ri documentation for redis-4.0.1
Done installing documentation for redis after 0 seconds
1 gem installed
5）安装rubygems
# yum install -y rubygems
到目前为止，我们的Ruby和运行redis-trib.rb需要的环境安装完成了。
3、Redis集群搭建
有了Ruby执行环境，可以开始将之前的6个实例组建成集群了。
redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
有三个master，有三个是slave。 后面跟上6个实例就好了，形式就是ip:port
【此处有坑】
第一坑
[root@itfirst src]# redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
-bash: redis-trib.rb: command not found
[root@itfirst src]# cp redis-trib.rb /usr/local/bin
需要将redis-trib.rb复制到/usr/local/bin目录下。
第二坑
[root@itfirst bin]# redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
>>> Creating cluster
[ERR] Node 192.168.186.91:7000 is not empty. Either the node already knows other nodes (check with CLUSTERNODES) or contains some key in database 0.
踩完第一坑后，继续执行，发现了第二坑，还好有度娘，但是网上各种说法都有（主要参照了《极客on之路》的博客），发现错误的原因是redis数据库没有清除。
http://blog.csdn.net/u014756827/article/details/52061987
[root@itfirst src]# redis-cli -h 192.168.186.91 -p 7001
192.168.186.91:7001> flushdb
OK
192.168.186.91:7001> quit
[root@itfirst src]# redis-cli -h 192.168.186.91 -p 7002
192.168.186.91:7002> flushdb
OK
192.168.186.91:7002> quit
[root@itfirst src]# redis-cli -h 192.168.186.91 -p 7003
192.168.186.91:7003> flushdb
OK
192.168.186.91:7003> quit
[root@itfirst src]# redis-cli -h 192.168.186.91 -p 7004
192.168.186.91:7004> flushdb
OK
192.168.186.91:7004> quit
[root@itfirst src]# redis-cli -h 192.168.186.91 -p 7005
192.168.186.91:7005> flushdb
OK
192.168.186.91:7005> quit
[root@itfirst src]# redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.186.91:7000
192.168.186.91:7001
192.168.186.91:7002
Adding replica 192.168.186.91:7003 to 192.168.186.91:7000
Adding replica 192.168.186.91:7004 to 192.168.186.91:7001
Adding replica 192.168.186.91:7005 to 192.168.186.91:7002
M: 61b2b608177374fd0382c872f996a2c25f62daac 192.168.186.91:7000
slots:0-5460,9189 (5462 slots) master
M: 50e678c98c31baa4ece1cba096cc34b4545456f3 192.168.186.91:7001
slots:5461-10922 (5462 slots) master
M: b8dc855a92d1c9a6e358380286a757011c40601d 192.168.186.91:7002
slots:9189,10923-16383 (5462 slots) master
S: 42392d8b4665500b3229b5c5b9dcebed311c9cdf 192.168.186.91:7003
replicates 61b2b608177374fd0382c872f996a2c25f62daac
S: 4e8cd9bae1dc0ffa63a3b8315e3f92b0490e65f8 192.168.186.91:7004
replicates 50e678c98c31baa4ece1cba096cc34b4545456f3
S: 3344981c3290c39b0d9f427842398c17de835293 192.168.186.91:7005
replicates b8dc855a92d1c9a6e358380286a757011c40601d
Can I set the above configuration? (type 'yes' to accept): yes
/usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis/client.rb:119:in `call': ERR Slot 9189 is already busy (Redis::CommandError)
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:2764:in `block in method_missing'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:45:in `block in synchronize'
from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/monitor.rb:214:in `mon_synchronize'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:45:in `synchronize'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:2763:in `method_missing'
from /usr/local/bin/redis-trib.rb:212:in `flush_node_config'
from /usr/local/bin/redis-trib.rb:776:in `block in flush_nodes_config'
from /usr/local/bin/redis-trib.rb:775:in `each'
from /usr/local/bin/redis-trib.rb:775:in `flush_nodes_config'
from /usr/local/bin/redis-trib.rb:1296:in `create_cluster_cmd'
from /usr/local/bin/redis-trib.rb:1696:in `<main>'
第三坑
[root@itfirst src]# redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.186.91:7000
192.168.186.91:7001
192.168.186.91:7002
Adding replica 192.168.186.91:7003 to 192.168.186.91:7000
Adding replica 192.168.186.91:7004 to 192.168.186.91:7001
Adding replica 192.168.186.91:7005 to 192.168.186.91:7002
M: 61b2b608177374fd0382c872f996a2c25f62daac 192.168.186.91:7000
slots:0-5460,9189 (5462 slots) master
M: 50e678c98c31baa4ece1cba096cc34b4545456f3 192.168.186.91:7001
slots:5461-10922 (5462 slots) master
M: b8dc855a92d1c9a6e358380286a757011c40601d 192.168.186.91:7002
slots:9189,10923-16383 (5462 slots) master
S: 42392d8b4665500b3229b5c5b9dcebed311c9cdf 192.168.186.91:7003
replicates 61b2b608177374fd0382c872f996a2c25f62daac
S: 4e8cd9bae1dc0ffa63a3b8315e3f92b0490e65f8 192.168.186.91:7004
replicates 50e678c98c31baa4ece1cba096cc34b4545456f3
S: 3344981c3290c39b0d9f427842398c17de835293 192.168.186.91:7005
replicates b8dc855a92d1c9a6e358380286a757011c40601d
Can I set the above configuration? (type 'yes' to accept): yes
/usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis/client.rb:119:in `call': ERR Slot 9189 is already busy (Redis::CommandError)
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:2764:in `block in method_missing'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:45:in `block in synchronize'
from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/monitor.rb:214:in `mon_synchronize'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:45:in `synchronize'
from /usr/local/rvm/gems/ruby-2.3.0/gems/redis-4.0.1/lib/redis.rb:2763:in `method_missing'
from /usr/local/bin/redis-trib.rb:212:in `flush_node_config'
from /usr/local/bin/redis-trib.rb:776:in `block in flush_nodes_config'
from /usr/local/bin/redis-trib.rb:775:in `each'
from /usr/local/bin/redis-trib.rb:775:in `flush_nodes_config'
from /usr/local/bin/redis-trib.rb:1296:in `create_cluster_cmd'
from /usr/local/bin/redis-trib.rb:1696:in `<main>'
还是度娘靠谱，在《redis 跨机器集群启动出错》博客中找到了答案。
这是由于之间创建集群没有成功,需要将nodes.conf和dir里面的文件全部删除。
[root@itfirst 7000]# find / -name "nodes-7000.conf"
/usr/local/redis-3.2.3/src/nodes-7000.conf
[root@itfirst 7000]# cd ../../
[root@itfirst src]# rm -rf nodes-700*
然后重启redis服务。
[root@itfirst src]# redis-trib.rb create --replicas 1 192.168.186.91:7000 192.168.186.91:7001 192.168.186.91:7002 192.168.186.91:7003 192.168.186.91:7004 192.168.186.91:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.186.91:7000
192.168.186.91:7001
192.168.186.91:7002
Adding replica 192.168.186.91:7003 to 192.168.186.91:7000
Adding replica 192.168.186.91:7004 to 192.168.186.91:7001
Adding replica 192.168.186.91:7005 to 192.168.186.91:7002
M: 319da27d8668a15d2d2d02afe433247694343459 192.168.186.91:7000
slots:0-5460 (5461 slots) master
M: 3da756265e301ac0210760f13e990473f87a3017 192.168.186.91:7001
slots:5461-10922 (5462 slots) master
M: 6f336da48c892d8e0c541a864765978ebfbca6d5 192.168.186.91:7002
slots:10923-16383 (5461 slots) master
S: ff4cf9d8a141d85c478b9af0358c93bca342c236 192.168.186.91:7003
replicates 319da27d8668a15d2d2d02afe433247694343459
S: 43c2e0d7799e84b449803a68d557c3431e9e047e 192.168.186.91:7004
replicates 3da756265e301ac0210760f13e990473f87a3017
S: 3f174fae106cb6cf7e7f21ed844895ed7c18f793 192.168.186.91:7005
replicates 6f336da48c892d8e0c541a864765978ebfbca6d5
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 192.168.186.91:7000)
M: 319da27d8668a15d2d2d02afe433247694343459 192.168.186.91:7000
slots:0-5460 (5461 slots) master
M: 3da756265e301ac0210760f13e990473f87a3017 192.168.186.91:7001
slots:5461-10922 (5462 slots) master
M: 6f336da48c892d8e0c541a864765978ebfbca6d5 192.168.186.91:7002
slots:10923-16383 (5461 slots) master
M: ff4cf9d8a141d85c478b9af0358c93bca342c236 192.168.186.91:7003
slots: (0 slots) master
replicates 319da27d8668a15d2d2d02afe433247694343459
M: 43c2e0d7799e84b449803a68d557c3431e9e047e 192.168.186.91:7004
slots: (0 slots) master
replicates 3da756265e301ac0210760f13e990473f87a3017
M: 3f174fae106cb6cf7e7f21ed844895ed7c18f793 192.168.186.91:7005
slots: (0 slots) master
replicates 6f336da48c892d8e0c541a864765978ebfbca6d5
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
4、验证集群状态
登录集群客户端，-c标识以集群方式登录
[root@itfirst src]# redis-cli -h 192.168.186.91 -c -p 7002
查看集群状态
192.168.186.91:7002> 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:124174
cluster_stats_messages_received:124174
192.168.186.91:7002> cluster nodes
319da27d8668a15d2d2d02afe433247694343459 192.168.186.91:7000 master - 0 1519465974307 1 connected 0-5460
3f174fae106cb6cf7e7f21ed844895ed7c18f793 192.168.186.91:7005 slave6f336da48c892d8e0c541a864765978ebfbca6d5 0 1519465971278 6 connected
6f336da48c892d8e0c541a864765978ebfbca6d5 192.168.186.91:7002 myself,master - 0 0 3 connected 10923-16383
3da756265e301ac0210760f13e990473f87a3017 192.168.186.91:7001 master - 0 1519465972288 2 connected 5461-10922
43c2e0d7799e84b449803a68d557c3431e9e047e 192.168.186.91:7004 slave3da756265e301ac0210760f13e990473f87a3017 0 1519465973298 5 connected
ff4cf9d8a141d85c478b9af0358c93bca342c236 192.168.186.91:7003 slave319da27d8668a15d2d2d02afe433247694343459 0 1519465969258 4 connected