Redis 好用指令紀錄

#檢查 Cluster 情況 (未登入 Redis node 時)：

redis-cli --cluster check <redis node domain or IP>:<port>

範例：

redis-cli --cluster check xxx.xxx.xxx:6379

修復 Redis Server Cluster Slot 分配不正常等 node 問題：

redis-cli --cluster fix xxx.xxx.xxx:6379

回應範例(以下為三組 Master node 和 Slave node，實際上可能會有更多組)：

xxx.xxx.xxx:6379 (1ba418d4...) -> 4 keys | 5461 slots | 1 slaves.
xxx.xxx.xxx:6381 (4131a66e...) -> 4 keys | 5461 slots | 1 slaves.
xxx.xxx.xxx:6380 (ba5a4554...) -> 4 keys | 5462 slots | 1 slaves.
[OK] 12 keys in 3 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node xxx.xxx.xxx:6379)
M: 1ba418d421ac322943423091360c909a549b3d39 xxx.xxx.xxx:6379
   slots:[0-5460] (5461 slots) master
   1 additional replica(s)
S: 431b199172871c4c61f4e2f48ed1b9117dd3e801 xxx.xxx.xxx:6384
   slots: (0 slots) slave
   replicates 1ba418d421ac322943423091360c909a549b3d39
S: 2fb427cf8acb3521c67c45fc2cfe1ac2a669a3c0 xxx.xxx.xxx:6383
   slots: (0 slots) slave
   replicates 4131a66e5cadfd91c48b824d5288ddb1445d8bd1
M: 4131a66e5cadfd91c48b824d5288ddb1445d8bd1 xxx.xxx.xxx:6381
   slots:[10923-16383] (5461 slots) master
   1 additional replica(s)
M: ba5a4554bc90d750de37a5da39b93dca896bab72 xxx.xxx.xxx:6380
   slots:[5461-10922] (5462 slots) master
   1 additional replica(s)
S: 70712afa54623608772bafd1926305e895d7d076 xxx.xxx.xxx:6382
   slots: (0 slots) slave
   replicates ba5a4554bc90d750de37a5da39b93dca896bab72
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.

在回應中， "M" 代表 Master node、"S" 代表依附於 Master node 的 "Slave node"，
Slave node 的 replicates 值指出了它依附的是哪一個 Master node

#登入 Redis node (會進入 Redis 互動 command line 模式，"-c" 代表 Cluster Mode)：

redis-cli -h xxx.xxx.xxx -p 6379 -c

#查看 Cluster 狀態(登入 Redis node 後)：

cluster info

回應範例：

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:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:3649
cluster_stats_messages_pong_sent:3775
cluster_stats_messages_sent:7424
cluster_stats_messages_ping_received:3770
cluster_stats_messages_pong_received:3646
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:7421
total_cluster_links_buffer_limit_exceeded:0

#啟動 Redis node：

redis-server <Redis config 檔的位置> --port <Redis node 的 port> --cluster-announce-ip "<Redis node 的 IP 或 hostname>"

範例：

redis-server /usr/local/etc/redis/redis.conf --port "6379" --cluster-announce-ip "xxx.xxx.xxx"

#建立 Redis Cluster：

redis-cli --cluster create <Redis node-1 IP or hostname:<port> <Redis node-2 IP or hostname:<port> ...<可多個 Redis node>....... --cluster-replicas <一個 Redis master node 要有幾個依附的 Redis slave node>

範例：

redis-cli --cluster create xxx.xxx.xxx:6379 xxx.xxx.xxx:6380 xxx.xxx.xxx:6381 xxx.xxx.xxx:6382 --cluster-replicas 1

#清除cluster中所有 node 的 key資料 (等同於對每個 cluster 中的所有 node 執行 flushall)

redis-cli --cluster call <cluster 中的任一node ip 或 hostname>:<Redis node 的 port> flushall

範例：

redis-cli --cluster call xxx.xxx.xxx:6379 flushall