Redis cluster reports an error cluster_ State:fail, how to solve and restore the cluster (IP problem / incomplete slot allocation problem)

Report errors

127.0.0.1:6379> set name tom        ---》 Test in redis Error reporting for data stored in the cluster 
-> Redirected to slot [5798] located at 192.168.3.2:6379
(error) CLUSTERDOWN The cluster is down

192.168.3.2:6379> cluster info
cluster_state:fail       ---》 Shows that the cluster status is off 
cluster_slots_assigned:16384
cluster_slots_ok:10923
cluster_slots_pfail:0
cluster_slots_fail:5461
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:6
cluster_my_epoch:2
cluster_stats_messages_ping_sent:2203
cluster_stats_messages_pong_sent:392
cluster_stats_messages_meet_sent:4
cluster_stats_messages_fail_sent:4
cluster_stats_messages_sent:2603
cluster_stats_messages_ping_received:391
cluster_stats_messages_pong_received:310
cluster_stats_messages_meet_received:1
cluster_stats_messages_fail_received:1
cluster_stats_messages_received:703

solve

  View all redis Log discovery redis-5 The container has been repeatedly connected 192.168.3.1:6379 This master node node-1

[[email protected] ~]# docker logs -f redis-5
......
1:S 28 May 2022 13:07:53.233 # Cluster state changed: fail
1:S 28 May 2022 13:07:53.442 * Connecting to MASTER 192.168.3.1:6379
1:S 28 May 2022 13:07:53.442 * MASTER <-> REPLICA sync started
1:S 28 May 2022 13:07:53.442 # Error condition on socket for SYNC: Connection refused
1:S 28 May 2022 13:07:54.481 * Connecting to MASTER 192.168.3.1:6379
1:S 28 May 2022 13:07:54.481 * MASTER <-> REPLICA sync started
......

  see node-1 Of redis Node profile redis.conf The nodes in the IP

[[email protected] ~]# cat /root/redis/node-1/conf/redis.conf
port 6379
bind 0.0.0.0
cluster-enabled yes
cluster-config-file nodes.conf   ---》redis Cluster node configuration file 
cluster-node-timeout 5000
cluster-announce-ip 192.168.3.11   ---》 You can see node-1 Node configuration file IP by 192.168.3.11
cluster-announce-port 6379
cluster-announce-bus-port 16379
appendonly yes

  View the current redis State of the cluster , In the form of arrays

192.168.3.2:6379> cluster slots    ---》 Current cluster state , In the form of arrays 
1) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "192.168.3.3"
      2) (integer) 6379
      3) "ff0d1d636f94d9b092e6012408c1d0918e00e6ed"
   4) 1) "192.168.3.4"
      2) (integer) 6379
      3) "2113cf366ad27ebd73585f03d368e77f03b1a2e1"
2) 1) (integer) 0
   2) (integer) 5460
   3) 1) "192.168.3.1"           ---》 You can see the of this node in the cluster IP yes 192.168.3.1
      2) (integer) 6379
      3) "c856c94ba8d2c55a0d176831bc85aa34a96fde88"
   4) 1) "192.168.3.5"
      2) (integer) 6379
      3) "d92ff5984ab29370af0adeaca71e7938c0287ca5"
3) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "192.168.3.2"
      2) (integer) 6379
      3) "8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3"
   4) 1) "192.168.3.6"
      2) (integer) 6379
      3) "2108a90495c147c675328f9b8b4fa49e2b856faf"

  see redis Cluster node configuration file nodes.conf

[[email protected] ~]# cat /root/redis/node-1/data/nodes.conf
c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.1:[email protected] myself,master - 0 1653743266000 1 connected 0-5460
d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:[email protected] slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743274000 5 connected
2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:[email protected] slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743275531 6 connected
2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:[email protected] slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743275531 4 connected
8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:[email protected] master - 0 1653743275531 2 connected 5461-10922
ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:[email protected] master - 0 1653743275000 3 connected 10923-16383
vars currentEpoch 6 lastVoteEpoch 0

[[email protected] ~]# cat /root/redis/node-2/data/nodes.conf
ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:[email protected] master - 0 1653743273233 3 connected 10923-16383
2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:[email protected] slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743271151 4 connected
c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.1:[email protected] master,fail - 1653743267074 1653743266961 1 connected 0-5460
d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:[email protected] slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743272000 1 connected
8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:[email protected] myself,master - 0 1653743271000 2 connected 5461-10922
2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:[email protected] slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743272194 6 connected
vars currentEpoch 6 lastVoteEpoch 0

  You can see redis Cluster configuration files for all nodes nodes.conf Medium is 192.168.3.1:6379, And node-1 Node redis.conf Inconsistencies in the documents .

  Batch modify all redis node nodes.conf This node in the file IP To configure

[[email protected] ~]# for i in $(seq 1 6); do \
> sed -i 's/192.168.3.1/192.168.3.11/' /root/redis/node-${i}/data/nodes.conf
> done

  View all modified redis colony nodes.conf file

[[email protected] ~]# cat /root/redis/node-1/data/nodes.conf 
c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:[email protected] myself,master - 0 1653743266000 1 connected 0-5460
d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:[email protected] slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743274000 5 connected
2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:[email protected] slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743275531 6 connected
2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:[email protected] slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743275531 4 connected
8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:[email protected] master - 0 1653743275531 2 connected 5461-10922
ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:[email protected] master - 0 1653743275000 3 connected 10923-16383
vars currentEpoch 6 lastVoteEpoch 0

[[email protected] ~]# cat /root/redis/node-2/data/nodes.conf
ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:[email protected] master - 0 1653743273233 3 connected 10923-16383
2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:[email protected] slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653743271151 4 connected
c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:[email protected] master,fail - 1653743267074 1653743266961 1 connected 0-5460
d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:[email protected] slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653743272000 1 connected
8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:[email protected] myself,master - 0 1653743271000 2 connected 5461-10922
2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:[email protected] slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653743272194 6 connected
vars currentEpoch 6 lastVoteEpoch 0
...
...

  Batch restart redis Cluster all node containers

[[email protected] ~]# docker restart $(docker ps | grep redis | awk '{print $1}')
dcd802a160c6
6e2f628457f6
f05d3dfb9c8b
220df78836e9
31e7b232f1d1
1de91b4d4e68

[[email protected] ~]# docker ps
CONTAINER ID   IMAGE                    COMMAND                  CREATED       STATUS       PORTS                                                                                      NAMES
6e2f628457f6   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6376->6379/tcp, :::6376->6379/tcp, 0.0.0.0:16376->16379/tcp, :::16376->16379/tcp   redis-6
f05d3dfb9c8b   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6375->6379/tcp, :::6375->6379/tcp, 0.0.0.0:16375->16379/tcp, :::16375->16379/tcp   redis-5
220df78836e9   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6374->6379/tcp, :::6374->6379/tcp, 0.0.0.0:16374->16379/tcp, :::16374->16379/tcp   redis-4
31e7b232f1d1   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6373->6379/tcp, :::6373->6379/tcp, 0.0.0.0:16373->16379/tcp, :::16373->16379/tcp   redis-3
1de91b4d4e68   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6372->6379/tcp, :::6372->6379/tcp, 0.0.0.0:16372->16379/tcp, :::16372->16379/tcp   redis-2
dcd802a160c6   redis:5.0.9-alpine3.11   "docker-entrypoint.s…"   3 hours ago   Up 2 hours   0.0.0.0:6371->6379/tcp, :::6371->6379/tcp, 0.0.0.0:16371->16379/tcp, :::16371->16379/tcp   redis-1

  Review redis State of the cluster

[[email protected] ~]# docker exec -it redis-1 /bin/sh ---》redis There is no bash Interpreter 
/data # redis-cli -c
127.0.0.1:6379> cluster info
cluster_state:ok      ---》 You can see redis The cluster status is already 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:236
cluster_stats_messages_pong_sent:233
cluster_stats_messages_sent:469
cluster_stats_messages_ping_received:233
cluster_stats_messages_pong_received:232
cluster_stats_messages_received:465

127.0.0.1:6379> cluster nodes
c856c94ba8d2c55a0d176831bc85aa34a96fde88 192.168.3.11:[email protected] master - 0 1653752958838 1 connected 0-5460
8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 192.168.3.2:[email protected] myself,master - 0 1653752957000 2 connected 5461-10922
2113cf366ad27ebd73585f03d368e77f03b1a2e1 192.168.3.4:[email protected] slave ff0d1d636f94d9b092e6012408c1d0918e00e6ed 0 1653752957804 4 connected
2108a90495c147c675328f9b8b4fa49e2b856faf 192.168.3.6:[email protected] slave 8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3 0 1653752957086 6 connected
ff0d1d636f94d9b092e6012408c1d0918e00e6ed 192.168.3.3:[email protected] master - 0 1653752958000 3 connected 10923-16383
d92ff5984ab29370af0adeaca71e7938c0287ca5 192.168.3.5:[email protected] slave c856c94ba8d2c55a0d176831bc85aa34a96fde88 0 1653752958529 1 connected

127.0.0.1:6379> cluster slots
1) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "192.168.3.2"
      2) (integer) 6379
      3) "8b01b1bc6202e1dc7ff9f15013d8200b10ecb3f3"
   4) 1) "192.168.3.6"
      2) (integer) 6379
      3) "2108a90495c147c675328f9b8b4fa49e2b856faf"
2) 1) (integer) 0
   2) (integer) 5460
   3) 1) "192.168.3.11"      ---》 You can see the of this node in the cluster IP Has been modified IP
      2) (integer) 6379
      3) "c856c94ba8d2c55a0d176831bc85aa34a96fde88"
   4) 1) "192.168.3.5"
      2) (integer) 6379
      3) "d92ff5984ab29370af0adeaca71e7938c0287ca5"
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "192.168.3.3"
      2) (integer) 6379
      3) "ff0d1d636f94d9b092e6012408c1d0918e00e6ed"
   4) 1) "192.168.3.4"
      2) (integer) 6379
      3) "2113cf366ad27ebd73585f03d368e77f03b1a2e1"

Another situation

  When the cluster reports an error cluster_state:fail when , Maybe it's because slot The problem of incomplete allocation makes the cluster unavailable . because redis To ensure cluster integrity , By default, when the cluster 16384 When any one of the slots is not assigned to a node , Whole redis The cluster will be unavailable . This is a protection measure for cluster integrity , Ensure that all slots are assigned to online redis node . In this case , Reassign these slots The cluster unavailability problem can be solved .

  In this case, you can take a look at this article ： Unassigned slots Problem solving

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