Redis叢集：Redis3.X環境搭建、查詢叢集資訊
redis叢集
ruby環境
redis叢集管理工具redis-trib.rb依賴ruby環境，首先需要安裝ruby環境：
安裝ruby
yum install ruby
yum install rubygems
安裝ruby和redis的介面程式
拷貝redis-3.0.0.gem至/usr/local下
執行：
gem install /usr/local/redis-3.0.0.gem
建立叢集：
叢集結點規劃
這裡在同一臺伺服器用不同的埠表示不同的redis伺服器，如下：
主節點：192.168.101.3:7001 192.168.101.3:7002 192.168.101.3:7003
從節點：192.168.101.3:7004 192.168.101.3:7005 192.168.101.3:7006
在/usr/local下建立redis-cluster目錄，其下建立7001、7002...7006目錄，如下：
將redis安裝目錄bin下的檔案拷貝到每個700X目錄內，同時將redis原始碼目錄src下的redis-trib.rb拷貝到redis-cluster目錄下。
修改每個700X目錄下的redis.conf配置檔案：
port XXXX
bind 192.168.101.3
cluster-enabled yes
啟動每個結點redis服務
分別進入7001、7002、...7006目錄，執行：
./redis-server ./redis.conf
檢視redis程序：
執行建立叢集命令
執行redis-trib.rb，此指令碼是ruby指令碼，它依賴ruby環境。
./redis-trib.rb create --replicas 1 192.168.101.3:7001 192.168.101.3:7002 192.168.101.3:7003 192.168.101.3:7004 192.168.101.3:7005 192.168.101.3:7006
說明：
redis叢集至少需要3個主節點，每個主節點有一個從節點總共6個節點
replicas指定為1表示每個主節點有一個從節點
注意：
如果執行時報如下錯誤：
[ERR] Node XXXXXX is not empty.
Either the node already knows other nodes (check with CLUSTER NODES) or contains some key in database 0
解決方法是刪除生成的配置檔案nodes.conf，如果不行則說明現在建立的結點包括了舊叢集的結點資訊，需要刪除redis的持久化檔案後再重啟redis，比如：appendonly.aof、dump.rdb
建立叢集輸出如下：
>>> Creating cluster
Connecting to node 192.168.101.3:7001: OK
Connecting to node 192.168.101.3:7002: OK
Connecting to node 192.168.101.3:7003: OK
Connecting to node 192.168.101.3:7004: OK
Connecting to node 192.168.101.3:7005: OK
Connecting to node 192.168.101.3:7006: OK
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.101.3:7001
192.168.101.3:7002
192.168.101.3:7003
Adding replica 192.168.101.3:7004 to 192.168.101.3:7001
Adding replica 192.168.101.3:7005 to 192.168.101.3:7002
Adding replica 192.168.101.3:7006 to 192.168.101.3:7003
M: cad9f7413ec6842c971dbcc2c48b4ca959eb5db4 192.168.101.3:7001
slots:0-5460 (5461 slots) master
M: 4e7c2b02f0c4f4cfe306d6ad13e0cfee90bf5841 192.168.101.3:7002
slots:5461-10922 (5462 slots) master
M: 1a8420896c3ff60b70c716e8480de8e50749ee65 192.168.101.3:7003
slots:10923-16383 (5461 slots) master
S: 69d94b4963fd94f315fba2b9f12fae1278184fe8 192.168.101.3:7004
replicates cad9f7413ec6842c971dbcc2c48b4ca959eb5db4
S: d2421a820cc23e17a01b597866fd0f750b698ac5 192.168.101.3:7005
replicates 4e7c2b02f0c4f4cfe306d6ad13e0cfee90bf5841
S: 444e7bedbdfa40714ee55cd3086b8f0d5511fe54 192.168.101.3:7006
replicates 1a8420896c3ff60b70c716e8480de8e50749ee65
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 192.168.101.3:7001)
M: cad9f7413ec6842c971dbcc2c48b4ca959eb5db4 192.168.101.3:7001
slots:0-5460 (5461 slots) master
M: 4e7c2b02f0c4f4cfe306d6ad13e0cfee90bf5841 192.168.101.3:7002
slots:5461-10922 (5462 slots) master
M: 1a8420896c3ff60b70c716e8480de8e50749ee65 192.168.101.3:7003
slots:10923-16383 (5461 slots) master
M: 69d94b4963fd94f315fba2b9f12fae1278184fe8 192.168.101.3:7004
slots: (0 slots) master
replicates cad9f7413ec6842c971dbcc2c48b4ca959eb5db4
M: d2421a820cc23e17a01b597866fd0f750b698ac5 192.168.101.3:7005
slots: (0 slots) master
replicates 4e7c2b02f0c4f4cfe306d6ad13e0cfee90bf5841
M: 444e7bedbdfa40714ee55cd3086b8f0d5511fe54 192.168.101.3:7006
slots: (0 slots) master
replicates 1a8420896c3ff60b70c716e8480de8e50749ee65
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.查詢叢集資訊
叢集建立成功登陸任意redis節點查詢叢集中的節點情況。
客戶端以叢集方式登陸：
說明：
./redis-cli -c -h 192.168.101.3 -p 7001
其中-c表示以叢集方式連線redis，-h指定ip地址，-p指定埠號
cluster nodes 查詢叢集結點資訊
cluster info 查詢叢集狀態資訊
