Redis集群環境搭建(實驗)
集群中至少有奇數個主節點,所以至少三個主節點,
每個節點至少一個備份節點,所以共6個節點(master和slave各3個)
節點信息: (我這裏準備了3臺主機,每臺主機運行一個master和一個slave)
節點1:192.168.2.100:6379 master
節點2:192.168.2.100:6380 slave
節點3:192.168.2.200:6379 master
節點4:192.168.2.200:6380 slave
節點5:192.168.2.201:6379 master
節點6:192.168.2.201:6380 slave
master和slave安裝路徑:
master:/usr/local/redis-3.0.6-6379
slave:/usr/local/redis-3.0.6-6380
master配置文件:
daemonize yes //開啟後臺運行
pidfile /var/run/redis_6379.pid //pid文件
port 6379 //端口
bind 192.168.2.100 //默認127.0.0.1,需要改為其他節點可訪問的地址
logfile "/usr/local/redis-3.0.6-6379/redis_6379.log" //log文件路徑
dir /usr/local/redis-3.0.6-6379/ //RDB文件路徑
appendonly yes //開啟AOF持久化
cluster-enabled yes //開啟集群
cluster-config-file nodes-6379.conf //集群配置文件
cluster-node-timeout 15000 //請求超時,默認15秒
slave配置文件:
daemonize yes
pidfile /var/run/redis_6380.pid
port 6380
bind 192.168.2.100
logfile "/usr/local/redis-3.0.6-6380/redis_6380.log"
dir /usr/local/redis-3.0.6-638/
appendonly yes
cluster-enabled yes
cluster-config-file nodes-6380.conf
cluster-node-timeout 15000
啟動redis
# redis-server redis.conf //6個節點
# ps -ef |grep redis
root 22584 1 0 17:41 ? 00:00:00 redis-server 192.168.2.100:6379 [cluster]
root 22599 1 0 17:41 ? 00:00:00 redis-server 192.168.2.100:6380 [cluster]
root 22606 6650 0 17:41 pts/0 00:00:00 grep --color=auto redis
安裝ruby環境:(redis-trib.rb命令,需要在ruby環境中執行)
# yum -y install ruby ruby-devel rubygems rpm-build
# gem install redis
Successfully installed redis-3.2.1
Parsing documentation for redis-3.2.1
1 gem installed
可能會遇到的報錯:
ERROR: Could not find a valid gem 'redis' (>= 0), here is why:
Unable to download data from https://rubygems.org/ - no such name (https://rubygems.org/latest_specs.4.8.gz)
手動下載:https://rubygems.global.ssl.fastly.net/gems/redis-3.2.1.gem
執行:# gem install -l ./redis-3.2.1.gem
創建集群:
將redis-trib.rb復制到/usr/local/bin目錄下
# cp /usr/local/redis-3.0.6-6379/src/redis-trib.rb /usr/local/bin/
# redis-trib.rb create --replicas 1 192.168.2.100:6379 192.168.2.100:6380 192.168.2.200:6379 192.168.2.200:6380 192.168.2.201:6379 192.168.2.201:6380 //創建集群
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.2.100:6379 //3個master節點
192.168.2.200:6379
192.168.2.201:6379
Adding replica 192.168.2.200:6380 to 192.168.2.100:6379 //3個slave節點
Adding replica 192.168.2.100:6380 to 192.168.2.200:6379
Adding replica 192.168.2.201:6380 to 192.168.2.201:6379
M: 098e7eb756b6047fde988ab3c0b7189e1724ecf5 192.168.2.100:6379
slots:0-5460 (5461 slots) master //hash slot [0-5460]
S: 7119dec91b086ca8fe69f7878fa42b1accd75f0f 192.168.2.100:6380
replicates 5844b4272c39456b0fdf73e384ff8c479547de47
M: 5844b4272c39456b0fdf73e384ff8c479547de47 192.168.2.200:6379
slots:5461-10922 (5462 slots) master //hash slot [5461-10922]
S: 227f51028bbe827f27b4e40ed7a08fcc7d8df969 192.168.2.200:6380
replicates 098e7eb756b6047fde988ab3c0b7189e1724ecf5
M: 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 192.168.2.201:6379
slots:10923-16383 (5461 slots) master //hash slot [10923-16383]
S: 2faf68564a70372cfc06c1afff197019cc6a39f3 192.168.2.201:6380
replicates 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69
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 192.168.2.100:6379)
M: 098e7eb756b6047fde988ab3c0b7189e1724ecf5 192.168.2.100:6379
slots:0-5460 (5461 slots) master
M: 7119dec91b086ca8fe69f7878fa42b1accd75f0f 192.168.2.100:6380
slots: (0 slots) master
replicates 5844b4272c39456b0fdf73e384ff8c479547de47
M: 5844b4272c39456b0fdf73e384ff8c479547de47 192.168.2.200:6379
slots:5461-10922 (5462 slots) master
M: 227f51028bbe827f27b4e40ed7a08fcc7d8df969 192.168.2.200:6380
slots: (0 slots) master
replicates 098e7eb756b6047fde988ab3c0b7189e1724ecf5
M: 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 192.168.2.201:6379
slots:10923-16383 (5461 slots) master
M: 2faf68564a70372cfc06c1afff197019cc6a39f3 192.168.2.201:6380
slots: (0 slots) master
replicates 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69
[OK] All nodes agree about slots configuration. //所有節點都同意槽配置
>>> Check for open slots... //開始檢查槽
>>> Check slots coverage... //檢查槽的覆蓋率
[OK] All 16384 slots covered. //所有的槽(16384個槽)都被覆蓋(分配)
到此,redis集群環境部署完成。
誤區一:
集群是去中心化的結構,對於集群來說,在整個集群結構中,數據只會存兩份:一份在master上,另一份在任意一個slave上,
千萬不要理解為,salve一定備份“自己對應的master”,每個slave,都對應任意一個master。
正常來說,6個節點都應該是獨立的IP,我們將master和salve放在了一個主機上,只是為了節省實驗資源。
誤區二:
結合上面說的,
既然每個master都能在任意slave上備份,配置1個slave不行嗎?
當然不行了,3個master對應了16384個hash slot,你弄個1個slave備份數據,
最多只能備份1/3的數據。
那我增大slave的配置,這下備份空間問題解決了吧?
當然不行了,3組hash slot,通過你備份後,變成了1組,你要進行計算合並吧,首先備份速度和效率上就受到了影響。
其次,如果有一個master掛掉,你1個salve如何恢復?
第一、集群不支持這個功能。再一個,你1個salve備份,恢復時,你要進行計算拆分吧,恢復速度上也不是很好。
Redis集群環境搭建(實驗)