redis-cluster安装和配置

redis-cluster是redis官方写的集群功能，目前还未加入稳定版，据说会在3.0上线的时候加入，但是开发版已经包含该功能

开发版的下载方式是git clone https://github.com/antirez/redis.git，前提是安装了git

安装配置过程参考官方已经出的教程http://redis.io/topics/cluster-tutorial，全英文

1、源码下载，make

2、新建6个instance，3个master，3个slave；

新建实例之前要改一下redis.conf的内容，先改端口号，再改下面的cluster配置项

################################ REDIS CLUSTER  ###############################

#

# Normal Redis instances can't be part of a Redis Cluster;only nodes that are

# started as cluster nodes can. In order to start a Redisinstance as a

# cluster node enable the cluster support uncommenting thefollowing:

#

cluster-enabled yes

# Every cluster node has a cluster configuration file. Thisfile is not

# intended to be edited by hand. It is created and updated byRedis nodes.

# Every Redis Cluster node requires a different clusterconfiguration file.

# Make sure that instances running in the same system does nothave

# overlapping cluster configuration file names.

#

cluster-config-file nodes-6379.conf

# Cluster node timeout is the amount of seconds a node must beunreachable

# for it to be considered in failure state.

# Most other internal time limits are multiplicators of thenode timeout.

#

cluster-node-timeout 15

# In order to setup your cluster make sure to read thedocumentation

# available at http://redis.io web site. 

3、src下面的ruby脚本，建立集群： --replicas 1的意思是每个master有1个slave。

./redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005

如果脚本报错：

custom_require.rb:36:in `require': cannot load such file -- redis (LoadError)
from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from ./redis-trib.rb:25:in `<main>'

那么说明Ruby的redis接口没有安装，可以通过sudo gem install redis 进行安装。

可能会询问是否保存设置

Can I set the above configuration? (type 'yes' to accept):

回答yes

再输出一连串信息后，会显示OK

[OK] All 16384 slots covered.

这样redis-cluster集群就启动了

查看集群目前状况：

$ redis-cli -c -p 7000
127.0.0.1:7000> 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:0
cluster_stats_messages_sent:8770
cluster_stats_messages_received:8770

测试存值取值：

127.0.0.1:7000> set foo bar
-> Redirected to slot [12182] located at 127.0.0.1:7002
OK
127.0.0.1:7002> set hello world
-> Redirected to slot [866] located at 127.0.0.1:7000
OK
127.0.0.1:7000> get foo
-> Redirected to slot [12182] located at 127.0.0.1:7002
"bar"
127.0.0.1:7000> get hello
-> Redirected to slot [866] located at 127.0.0.1:7000
"world"