背景：
Redis Cluster 在5.0之后取消了ruby腳本 redis-trib.rb的支持（手動命令行添加集群的方式不變），集合到redis-cli里，避免了再安裝ruby的相關環境。直接使用redis-clit的參數--cluster 來取代。為方便自己后面查詢就說明下如何使用該命令進行Cluster的創建和管理，關於Cluster的相關說明可以查看官網或則Redis Cluster部署、管理和測試。
環境：
系統版本：Ubuntu 14.04 Redis版本：5.0.5 機器IP：192.168.163.132
說明：redis-cli --cluster help
redis-cli --cluster help
Cluster Manager Commands:
create host1:port1 ... hostN:portN #創建集群
--cluster-replicas <arg> #從節點個數
check host:port #檢查集群
--cluster-search-multiple-owners #檢查是否有槽同時被分配給了多個節點
info host:port #查看集群狀態
fix host:port #修復集群
--cluster-search-multiple-owners #修復槽的重復分配問題
reshard host:port #指定集群的任意一節點進行遷移slot，重新分slots
--cluster-from <arg> #需要從哪些源節點上遷移slot，可從多個源節點完成遷移，以逗號隔開，傳遞的是節點的node id，還可以直接傳遞--from all，這樣源節點就是集群的所有節點，不傳遞該參數的話，則會在遷移過程中提示用戶輸入
--cluster-to <arg> #slot需要遷移的目的節點的node id，目的節點只能填寫一個，不傳遞該參數的話，則會在遷移過程中提示用戶輸入
--cluster-slots <arg> #需要遷移的slot數量，不傳遞該參數的話，則會在遷移過程中提示用戶輸入。
--cluster-yes #指定遷移時的確認輸入
--cluster-timeout <arg> #設置migrate命令的超時時間
--cluster-pipeline <arg> #定義cluster getkeysinslot命令一次取出的key數量，不傳的話使用默認值為10
--cluster-replace #是否直接replace到目標節點
rebalance host:port #指定集群的任意一節點進行平衡集群節點slot數量
--cluster-weight <node1=w1...nodeN=wN> #指定集群節點的權重
--cluster-use-empty-masters #設置可以讓沒有分配slot的主節點參與，默認不允許
--cluster-timeout <arg> #設置migrate命令的超時時間
--cluster-simulate #模擬rebalance操作，不會真正執行遷移操作
--cluster-pipeline <arg> #定義cluster getkeysinslot命令一次取出的key數量，默認值為10
--cluster-threshold <arg> #遷移的slot閾值超過threshold，執行rebalance操作
--cluster-replace #是否直接replace到目標節點
add-node new_host:new_port existing_host:existing_port #添加節點，把新節點加入到指定的集群，默認添加主節點
--cluster-slave #新節點作為從節點，默認隨機一個主節點
--cluster-master-id <arg> #給新節點指定主節點
del-node host:port node_id #刪除給定的一個節點，成功后關閉該節點服務
call host:port command arg arg .. arg #在集群的所有節點執行相關命令
set-timeout host:port milliseconds #設置cluster-node-timeout
import host:port #將外部redis數據導入集群
--cluster-from <arg> #將指定實例的數據導入到集群
--cluster-copy #migrate時指定copy
--cluster-replace #migrate時指定replace
help
For check, fix, reshard, del-node, set-timeout you can specify the host and port of any working node in the cluster.
注意：Redis Cluster最低要求是3個主節點，如果需要集群需要認證，則在最后加入 -a xx 即可。
① 創建集群主節點
redis-cli --cluster create 192.168.163.132:6379 192.168.163.132:6380 192.168.163.132:6381
>>> Performing hash slots allocation on 3 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master Can I set the above configuration? (type 'yes' to accept): yes #slot分配 >>> 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 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered.
② 創建集群主從節點
/redis-cli --cluster create 192.168.163.132:6379 192.168.163.132:6380 192.168.163.132:6381 192.168.163.132:6382 192.168.163.132:6383 192.168.163.132:6384 --cluster-replicas 1
說明：--cluster-replicas 參數為數字，1表示每個主節點需要1個從節點。
>>> Performing hash slots allocation on 6 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 Adding replica 192.168.163.132:6383 to 192.168.163.132:6379 Adding replica 192.168.163.132:6384 to 192.168.163.132:6380 Adding replica 192.168.163.132:6382 to 192.168.163.132:6381 >>> Trying to optimize slaves allocation for anti-affinity [WARNING] Some slaves are in the same host as their master M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 replicates 56005b9413cbf225783906307a2631109e753f8f S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 replicates 117457eab5071954faab5e81c3170600d5192270 S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 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 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master 1 additional replica(s) M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master 1 additional replica(s) S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered.
通過該方式創建的帶有從節點的機器不能夠自己手動指定主節點，所以如果需要指定的話，需要自己手動指定，先使用①或③創建好主節點后，再通過④來處理。
③ 添加集群主節點
redis-cli --cluster add-node 192.168.163.132:6382 192.168.163.132:6379
說明：為一個指定集群添加節點，需要先連到該集群的任意一個節點IP（192.168.163.132:6379），再把新節點加入。該2個參數的順序有要求：新加入的節點放前
>>> Adding node 192.168.163.132:6382 to cluster 192.168.163.132:6379 >>> Performing Cluster Check (using node 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Send CLUSTER MEET to node 192.168.163.132:6382 to make it join the cluster. [OK] New node added correctly.
④ 添加集群從節點
redis-cli --cluster add-node 192.168.163.132:6382 192.168.163.132:6379 --cluster-slave --cluster-master-id 117457eab5071954faab5e81c3170600d5192270
說明：把6382節點加入到6379節點的集群中，並且當做node_id為 117457eab5071954faab5e81c3170600d5192270 的從節點。如果不指定 --cluster-master-id 會隨機分配到任意一個主節點。
>>> Adding node 192.168.163.132:6382 to cluster 192.168.163.132:6379 >>> Performing Cluster Check (using node 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Send CLUSTER MEET to node 192.168.163.132:6382 to make it join the cluster. Waiting for the cluster to join .. >>> Configure node as replica of 192.168.163.132:6379.
⑤ 刪除節點
redis-cli --cluster del-node 192.168.163.132:6384 f6a6957421b80409106cb36be3c7ba41f3b603ff
說明：指定IP、端口和node_id 來刪除一個節點，從節點可以直接刪除，主節點不能直接刪除，刪除之后，該節點會被shutdown。
刪除從節點： redis-cli --cluster del-node 192.168.163.132:6384 f6a6957421b80409106cb36be3c7ba41f3b603ff >>> Removing node f6a6957421b80409106cb36be3c7ba41f3b603ff from cluster 192.168.163.132:6384 >>> Sending CLUSTER FORGET messages to the cluster... >>> SHUTDOWN the node. 刪除主節點： redis-cli --cluster del-node 192.168.163.132:6380 815da8448f5d5a304df0353ca10d8f9b77016b28 >>> Removing node 815da8448f5d5a304df0353ca10d8f9b77016b28 from cluster 192.168.163.132:6380 [ERR] Node 192.168.163.132:6380 is not empty! Reshard data away and try again.
注意：當被刪除掉的節點重新起來之后不能自動加入集群，但其和主的復制還是正常的，也可以通過該節點看到集群信息（通過其他正常節點已經看不到該被del-node節點的信息）。
如果想要再次加入集群，則需要先在該節點執行cluster reset，再用add-node進行添加，進行增量同步復制。
到此，目前整個集群的狀態如下：
192.168.163.132:6379> cluster nodes 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380@16380 master - 0 1569748297177 2 connected 5461-10922 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383@16383 slave 56005b9413cbf225783906307a2631109e753f8f 0 1569748295000 4 connected 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382@16382 slave 815da8448f5d5a304df0353ca10d8f9b77016b28 0 1569748295000 5 connected 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379@16379 myself,master - 0 1569748297000 1 connected 0-5460 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381@16381 master - 0 1569748295000 3 connected 10923-16383 f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384@16384 slave 117457eab5071954faab5e81c3170600d5192270 0 1569748298185 6 connected
⑥ 檢查集群
redis-cli --cluster check 192.168.163.132:6384 --cluster-search-multiple-owners
說明：任意連接一個集群節點，進行集群狀態檢查
redis-cli --cluster check 192.168.163.132:6384 --cluster-search-multiple-owners 192.168.163.132:6380 (815da844...) -> 0 keys | 5462 slots | 1 slaves. 192.168.163.132:6381 (56005b94...) -> 0 keys | 5461 slots | 1 slaves. 192.168.163.132:6379 (117457ea...) -> 2 keys | 5461 slots | 1 slaves. [OK] 2 keys in 3 masters. 0.00 keys per slot on average. >>> Performing Cluster Check (using node 192.168.163.132:6384) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master 1 additional replica(s) M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master 1 additional replica(s) [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Check for multiple slot owners...
⑦ 集群信息查看
redis-cli --cluster info 192.168.163.132:6384
說明：檢查key、slots、從節點個數的分配情況
/redis-cli --cluster info 192.168.163.132:6384 192.168.163.132:6380 (815da844...) -> 0 keys | 5462 slots | 1 slaves. 192.168.163.132:6381 (56005b94...) -> 0 keys | 5461 slots | 1 slaves. 192.168.163.132:6379 (117457ea...) -> 2 keys | 5461 slots | 1 slaves. [OK] 2 keys in 3 masters. 0.00 keys per slot on average.
⑧ 修復集群
redis-cli --cluster fix 192.168.163.132:6384 --cluster-search-multiple-owners
說明：修復集群和槽的重復分配問題
redis-cli --cluster fix 192.168.163.132:6384 --cluster-search-multiple-owners 192.168.163.132:6380 (815da844...) -> 0 keys | 5462 slots | 1 slaves. 192.168.163.132:6381 (56005b94...) -> 0 keys | 5461 slots | 1 slaves. 192.168.163.132:6379 (117457ea...) -> 2 keys | 5461 slots | 1 slaves. [OK] 2 keys in 3 masters. 0.00 keys per slot on average. >>> Performing Cluster Check (using node 192.168.163.132:6384) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master 1 additional replica(s) M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master 1 additional replica(s) [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Check for multiple slot owners...
⑨ 設置集群的超時時間
redis-cli --cluster set-timeout 192.168.163.132:6382 10000
說明：連接到集群的任意一節點來設置集群的超時時間參數cluster-node-timeout
redis-cli --cluster set-timeout 192.168.163.132:6382 10000 >>> Reconfiguring node timeout in every cluster node... *** New timeout set for 192.168.163.132:6382 *** New timeout set for 192.168.163.132:6384 *** New timeout set for 192.168.163.132:6383 *** New timeout set for 192.168.163.132:6379 *** New timeout set for 192.168.163.132:6381 *** New timeout set for 192.168.163.132:6380 >>> New node timeout set. 6 OK, 0 ERR.
⑩ 集群中執行相關命令
redis-cli --cluster call 192.168.163.132:6381 config set requirepass cc redis-cli -a cc --cluster call 192.168.163.132:6381 config set masterauth cc redis-cli -a cc --cluster call 192.168.163.132:6381 config rewrite
說明：連接到集群的任意一節點來對整個集群的所有節點進行設置。
redis-cli --cluster call 192.168.163.132:6381 config set cluster-node-timeout 12000 >>> Calling config set cluster-node-timeout 12000 192.168.163.132:6381: OK 192.168.163.132:6383: OK 192.168.163.132:6379: OK 192.168.163.132:6384: OK 192.168.163.132:6382: OK 192.168.163.132:6380: OK
...
...
到此，相關集群的基本操作已經介紹完，現在說明集群遷移的相關操作。
遷移相關
① 在線遷移slot ：在線把集群的一些slot從集群原來slot節點遷移到新的節點，即可以完成集群的在線橫向擴容和縮容。有2種方式進行遷移
一是根據提示來進行操作：
直接連接到集群的任意一節點 redis-cli -a cc --cluster reshard 192.168.163.132:6379
信息如下：
redis-cli -a cc --cluster reshard 192.168.163.132:6379 Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe. >>> Performing Cluster Check (using node 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master 1 additional replica(s) M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master 1 additional replica(s) S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. How many slots do you want to move (from 1 to 16384)? 1 What is the receiving node ID? 815da8448f5d5a304df0353ca10d8f9b77016b28 Please enter all the source node IDs. Type 'all' to use all the nodes as source nodes for the hash slots. Type 'done' once you entered all the source nodes IDs. Source node #1: 117457eab5071954faab5e81c3170600d5192270 Source node #2: done Ready to move 1 slots. Source nodes: M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[0-5460] (5461 slots) master 1 additional replica(s) Destination node: M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[5461-10922] (5462 slots) master 1 additional replica(s) Resharding plan: Moving slot 0 from 117457eab5071954faab5e81c3170600d5192270 Do you want to proceed with the proposed reshard plan (yes/no)? yes Moving slot 0 from 192.168.163.132:6379 to 192.168.163.132:6380:
二是根據參數進行操作：
redis-cli -a cc --cluster reshard 192.168.163.132:6379 --cluster-from 117457eab5071954faab5e81c3170600d5192270 --cluster-to 815da8448f5d5a304df0353ca10d8f9b77016b28 --cluster-slots 10 --cluster-yes --cluster-timeout 5000 --cluster-pipeline 10 --cluster-replace
說明：連接到集群的任意一節點來對指定節點指定數量的slot進行遷移到指定的節點。
>>> Performing Cluster Check (using node 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[11-5460] (5450 slots) master 1 additional replica(s) M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[0-10],[5461-10922] (5473 slots) master 1 additional replica(s) S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. Ready to move 10 slots. Source nodes: M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[11-5460] (5450 slots) master 1 additional replica(s) Destination node: M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[0-10],[5461-10922] (5473 slots) master 1 additional replica(s) Resharding plan: Moving slot 11 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 12 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 13 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 14 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 15 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 16 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 17 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 18 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 19 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 20 from 117457eab5071954faab5e81c3170600d5192270 Moving slot 11 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 12 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 13 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 14 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 15 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 16 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 17 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 18 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 19 from 192.168.163.132:6379 to 192.168.163.132:6380: Moving slot 20 from 192.168.163.132:6379 to 192.168.163.132:6380:
② 平衡（rebalance）slot ：
1）平衡集群中各個節點的slot數量
redis-cli -a cc --cluster rebalance 192.168.163.132:6379
>>> Performing Cluster Check (using node 192.168.163.132:6379) [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Rebalancing across 3 nodes. Total weight = 3.00 Moving 522 slots from 192.168.163.132:6380 to 192.168.163.132:6379 ########################################################################################################################################################################################################################################################################################################################################################################################################################################################################################################################################## Moving 500 slots from 192.168.163.132:6380 to 192.168.163.132:6381 ####################################################################################################################################################################################################################################################################################################################################################################################################################################################################################################################
2）根據集群中各個節點設置的權重等平衡slot數量（不執行，只模擬）
redis-cli -a cc --cluster rebalance --cluster-weight 117457eab5071954faab5e81c3170600d5192270=5 815da8448f5d5a304df0353ca10d8f9b77016b28=4 56005b9413cbf225783906307a2631109e753f8f=3 --cluster-simulate 192.168.163.132:6379
③ 導入集群
redis-cli --cluster import 192.168.163.132:6379 --cluster-from 192.168.163.132:9021 --cluster-replace
說明：外部Redis實例（9021）導入到集群中的任意一節點。
>>> Importing data from 192.168.163.132:9021 to cluster 192.168.163.132:6379 >>> Performing Cluster Check (using node 192.168.163.132:6379) M: 117457eab5071954faab5e81c3170600d5192270 192.168.163.132:6379 slots:[1366-5961],[11423-12287] (5461 slots) master 1 additional replica(s) M: 815da8448f5d5a304df0353ca10d8f9b77016b28 192.168.163.132:6380 slots:[1365],[5962-11422] (5462 slots) master 1 additional replica(s) S: 0c21b6cee354594a23f4d5abf0d01b48bdc96d55 192.168.163.132:6383 slots: (0 slots) slave replicates 56005b9413cbf225783906307a2631109e753f8f S: 3a1d04983ab6c4ae853f9602dd922d4ebadc4dbf 192.168.163.132:6382 slots: (0 slots) slave replicates 815da8448f5d5a304df0353ca10d8f9b77016b28 M: 56005b9413cbf225783906307a2631109e753f8f 192.168.163.132:6381 slots:[0-1364],[12288-16383] (5461 slots) master 1 additional replica(s) S: f6a6957421b80409106cb36be3c7ba41f3b603ff 192.168.163.132:6384 slots: (0 slots) slave replicates 117457eab5071954faab5e81c3170600d5192270 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. *** Importing 97847 keys from DB 0 Migrating 9223372011174675807 to 192.168.163.132:6381: OK Migrating 9223372033047675807 to 192.168.163.132:6381: OK ... ...
注意：測試下來發現參數--cluster-replace沒有用，如果集群中已經包含了某個key，在導入的時候會失敗，不會覆蓋，只有清空集群key才能導入。
*** Importing 97847 keys from DB 0 Migrating 9223372011174675807 to 192.168.163.132:6381: Source 192.168.163.132:9021 replied with error: ERR Target instance replied with error: BUSYKEY Target key name already exists
並且發現如果集群設置了密碼，也會導入失敗，需要設置集群密碼為空才能進行導入（call）。通過monitor（9021）的時候發現，在migrate的時候需要密碼進行auth認證。
總結：
Redis Cluster 通過redis-cli --cluster來創建和管理集群的方式和 redis-trib.rb腳本絕大部分都是一樣的，所以對於比較熟悉 redis-trib.rb 腳本的，使用--cluster也非常順手。