问题描述：执行redis-cli命令创建redis集群时报错“Could not connect to Redis at IP:端口: No route to host”，如下所示：

数据库：redis 6.2.6

系统：rhel 7.9

1、异常重现

[root@leo-redis626-a src]# /usr/local/src/redis-6.2.6/src/redis-cli --cluster create --cluster-replicas 1 \

> 192.168.133.100:8001 192.168.133.100:8002 \

> 192.168.133.101:8001 192.168.133.101:8002 \

> 192.168.133.102:8001 192.168.133.102:8002

Could not connect to Redis at 192.168.133.101:8001: No route to host

2、异常原因

该问题是在远程访问redis时出现，原因为服务器防火墙开启导致.

3、解决方案

--此处关闭三台服务器防火墙.

[root@leo-redis626-a src]# systemctl stop firewalld

[root@leo-redis626-a src]# systemctl disable firewalld

[root@leo-redis626-b src]# systemctl stop firewalld

[root@leo-redis626-b src]# systemctl disable firewalld

[root@leo-redis626-c src]# systemctl stop firewalld

[root@leo-redis626-c src]# systemctl disable firewalld

--此后重新执行redis-cli命令创建集群.

[root@leo-redis626-a src]# /usr/local/src/redis-6.2.6/src/redis-cli --cluster create --cluster-replicas 1 \

> 192.168.133.100:8001 192.168.133.100:8002 \

> 192.168.133.101:8001 192.168.133.101:8002 \

> 192.168.133.102:8001 192.168.133.102:8002

>>> Performing hash slots allocation on 6 nodes...

Master[0] -> Slots 0 - 5460

Master[1] -> Slots 5461 - 10922

Master[2] -> Slots 10923 - 16383

Adding replica 192.168.133.101:8002 to 192.168.133.100:8001

Adding replica 192.168.133.102:8002 to 192.168.133.101:8001

Adding replica 192.168.133.100:8002 to 192.168.133.102:8001

M: c036f0322c2f8bdd04b1f156f8ff7c29804eb28b 192.168.133.100:8001

   slots:[0-5460] (5461 slots) master

S: 6bf0eff5c1874da48cb64df57accac8eaf7aa57d 192.168.133.100:8002

   replicates 81c45df99418144728954cda61dfa9fb3e1c5b3f

M: 6d9ca761fc09c83b6a3c2273a36b565c4c525ac3 192.168.133.101:8001

   slots:[5461-10922] (5462 slots) master

S: 9f2b2480fecb0a193fdb2feed8c507c7c664cd74 192.168.133.101:8002

   replicates c036f0322c2f8bdd04b1f156f8ff7c29804eb28b

M: 81c45df99418144728954cda61dfa9fb3e1c5b3f 192.168.133.102:8001

   slots:[10923-16383] (5461 slots) master

S: 5d9ff4989ef75877c6683ece2cc39f22fa4160e6 192.168.133.102:8002

   replicates 6d9ca761fc09c83b6a3c2273a36b565c4c525ac3

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 192.168.133.100:8001)

M: c036f0322c2f8bdd04b1f156f8ff7c29804eb28b 192.168.133.100:8001

   slots:[0-5460] (5461 slots) master

   1 additional replica(s)

S: 5d9ff4989ef75877c6683ece2cc39f22fa4160e6 192.168.133.102:8002

   slots: (0 slots) slave

   replicates 6d9ca761fc09c83b6a3c2273a36b565c4c525ac3

S: 6bf0eff5c1874da48cb64df57accac8eaf7aa57d 192.168.133.100:8002

   slots: (0 slots) slave

   replicates 81c45df99418144728954cda61dfa9fb3e1c5b3f

M: 6d9ca761fc09c83b6a3c2273a36b565c4c525ac3 192.168.133.101:8001

   slots:[5461-10922] (5462 slots) master

   1 additional replica(s)

M: 81c45df99418144728954cda61dfa9fb3e1c5b3f 192.168.133.102:8001

   slots:[10923-16383] (5461 slots) master

   1 additional replica(s)

S: 9f2b2480fecb0a193fdb2feed8c507c7c664cd74 192.168.133.101:8002

   slots: (0 slots) slave

   replicates c036f0322c2f8bdd04b1f156f8ff7c29804eb28b

[OK] All nodes agree about slots configuration.

>>> Check for open slots...

>>> Check slots coverage...

[OK] All 16384 slots covered.

 

说明：如上所示，redis集群成功创建.