redis叢集3 2臺機器遷移為3臺機器
阿新 • • 發佈：2018-12-25
環境
系統：Centos6.6
軟體：redis 3.0.3
背景
因為2個機器搭建的redis叢集一旦1臺機器損壞，叢集依然不可用,為了解決該問題，決定新增一個機器，組成3臺機器的高可用環境。
叢集節點：
把原來的5.17 5.18 的7002埠去掉，新增5.16的7000 7001
遷移前主機 埠 遷移後主機 埠 10.112.5.17 7000 10.112.5.16 7000 10.112.5.17 7001 10.112.5.16 7001 10.112.5.17 7002 10.112.5.17 7000 10.112.5.18 7000 10.112.5.17 7001 10.112.5.18 7001 10.112.5.18 7000 10.112.5.18 7002 10.112.5.18 7001
2個機器的原始狀態：
[[email protected] ~]$ redis-cli -p 7000 -c cluster nodes|awk '{print $1,$2,$3,$4,$NF}'| sort -k2
231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.17:7000 myself,master - 5461-10922936482ede8b9e8b94eeb7d947e51ef635e5173df 10.112.5.17:7001 slave c3312b79d40e6b90eb856c3e52d0fae21ba217e7 connected
因為需要摘除7002節點，所以找到7002節點
[[email protected] ~]$ redis-cli -p 7000 -c cluster nodes|awk '{print $1,$2,$3,$4,$NF}'| sort -k2|grep :70022304aalsdkjfalsjdflkajsfj23rklwj10932je9 10.112.5.17:7002 slave 231b544622793b0b69e88a286ac8b46d211c8172 connected
e442abf8ec244a697a203c67092fc184b45220bb 10.112.5.18:7002 master - 10923-16383從上面的節點資訊可以看到
10.112.5.17:7002是slave節點，可以直接摘除，
10.112.5.18:7002是master節點，需要先變成從節點，再進行摘除：
現在先把10.112.5.18:7002變成從節點
1 先kill掉10.112.5.18:7002的程序，讓salve這個節點下線，讓他的slave節點變成主
ps -ef|grep 7002 |awk '{print $2}'|kill
2.檢視節點狀態
redis-cli -c -p 7000 cluster nodes
發現10.112.5.18:7002 已經下線，並且10.112.5.18:7001 已經變成了主節點
3.啟動10.112.5.18:7002 ,讓他也變成從節點
redis-server 7002/7002.conf
redis-cli -c -p 7000 cluster nodes
檢視節點狀態後，10.112.5.18:7002已經變成從節點
此時2個節點已經變成從節點，可以直接執行摘除操作。
為了安全考慮，先把2個新的節點新增到叢集，再執行節點摘除操作。
[[email protected] ~]$ redis-cli -p 7000 -c cluster nodes|awk '{print $1,$2,$3,$4,$NF}'| sort -k2
231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.17:7000 myself,master - 5461-10922936482ede8b9e8b94eeb7d947e51ef635e5173df 10.112.5.17:7001 slave c3312b79d40e6b90eb856c3e52d0fae21ba217e7 connected
2304aalsdkjfalsjdflkajsfj23rklwj10932je9 10.112.5.17:7002 slave 231b544622793b0b69e88a286ac8b46d211c8172 connected
c3312b79d40e6b90eb856c3e52d0fae21ba217e7 10.112.5.18:7000 master - 0-5460
fb13b382748edee5e329db61af6ccbe5a426dade 10.112.5.18:7001 master - 10923-16383
e442abf8ec244a697a203c67092fc184b45220bb 10.112.5.18:7002 slave fb13b382748edee5e329db61af6ccbe5a426dade connected新的節點是為了替換2個7002埠的從節點，所以找到2個7002埠對應的2個主節點：
231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.17:7000 myself,master - 5461-10922
fb13b382748edee5e329db61af6ccbe5a426dade 10.112.5.18:7001 master - 10923-16383
執行新增節點操作：
命令用法：redis-trib.rb add-node newip:newport IP:port
redis-trib.rb add-node --slave --master-id 231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.16:7000 10.112.5.17:7000
redis-trib.rb add-node --slave --master-id fb13b382748edee5e329db61af6ccbe5a426dade 10.112.5.16:7001 10.112.5.17:7000
新增2個新的從節點後，檢視狀態,一共8個節點
[[email protected] ~]$ redis-cli -p 7000 -c cluster nodes|awk '{print $1,$2,$3,$4,$NF}'| sort -k2
e442abf8ec244a697a203c67092fc184b45220bb 10.112.5.16:7001 slave fb13b382748edee5e329db61af6ccbe5a426dade connected
341a85b5ca42f8bb7baf707579025fa352c822b6 10.112.5.16:7000 slave 231b544622793b0b69e88a286ac8b46d211c8172 connected
231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.17:7000 myself,master - 5461-10922936482ede8b9e8b94eeb7d947e51ef635e5173df 10.112.5.17:7001 slave c3312b79d40e6b90eb856c3e52d0fae21ba217e7 connected
2304aalsdkjfalsjdflkajsfj23rklwj10932je9 10.112.5.17:7002 slave 231b544622793b0b69e88a286ac8b46d211c8172 connected
c3312b79d40e6b90eb856c3e52d0fae21ba217e7 10.112.5.18:7000 master - 0-5460
fb13b382748edee5e329db61af6ccbe5a426dade 10.112.5.18:7001 master - 10923-16383
e442abf8ec244a697a203c67092fc184b45220bb 10.112.5.18:7002 slave fb13b382748edee5e329db61af6ccbe5a426dade connected刪除2個7002埠的幾點：
redis-trib.rb del-node 10.112.5.17:7001 e442abf8ec244a697a203c67092fc184b45220bb
redis-trib.rb del-node 10.112.5.17:7001 fb13b382748edee5e329db61af6ccbe5a426dade
遷移後的節點狀態：
[[email protected] ~]$ redis-cli -p 7000 -c cluster nodes|awk '{print $1,$2,$3,$4,$NF}'
e442abf8ec244a697a203c67092fc184b45220bb 10.112.5.16:7001 slave fb13b382748edee5e329db61af6ccbe5a426dade connected
936482ede8b9e8b94eeb7d947e51ef635e5173df 10.112.5.17:7001 slave c3312b79d40e6b90eb856c3e52d0fae21ba217e7 connected
231b544622793b0b69e88a286ac8b46d211c8172 10.112.5.17:7000 myself,master - 5461-10922341a85b5ca42f8bb7baf707579025fa352c822b6 10.112.5.16:7000 slave 231b544622793b0b69e88a286ac8b46d211c8172 connected
c3312b79d40e6b90eb856c3e52d0fae21ba217e7 10.112.5.18:7000 master - 0-5460
fb13b382748edee5e329db61af6ccbe5a426dade 10.112.5.18:7001 master - 10923-16383