Highly available Redis (10): Redis Native Command Build cluster

1. Main steps to build Redis cluster

1. Configure the node to open
2.meet
3. Assign slot
4. Master-slave relationship distribution

2. Environmental statement

Two virtual machines with IP addresses: 192.168.81.100 and 192.168.81.101
Both virtual machine operating systems are: CentOS 7.5 64-bit
Two virtual machine system instructions:
     Install Redis using yum mode
     Turn off the firewalld firewall
Use the 7000, 7001, and 7002 ports of two virtual machines to build a three-master three-slave Redis Cluster
     Among them, the 192.168.81.100 host three ports start the Redis Server as the master node.
     The 192.168.81.101 host has three ports to start the Redis Server as a slave node.

3. Step 3.1 operation on the 192.168.81.100 virtual machine

[[email protected] etc]# cd /opt
[[email protected] opt]# mkdir config
[[email protected] opt]# cd config
[[email protected] config]# vi redis_7000.conf # Create the configuration file required for 7000 port operation. The file contents are as follows:
    Port 7000
    Daemonize yes
    Dir ‘/var/lib/redis‘
    Logfile ‘/var/log/redis/redis_7000.log‘
    Dbfilename ‘redis_7000.data‘
    Cluster-enabled yes
    Cluster-config-file nodes-7000.conf
    Cluster-require-full-coverage no
[[email protected] config]# sed ‘s/7000/7001/g‘ redis_7000.conf > redis_7001.conf # Replace 7000 in redis_7000.conf with 7001 and generate redis_7001.conf file
[[email protected] config]# sed ‘s/7000/7002/g‘ redis_7000.conf > redis_7002.conf # Replace 7000 in redis_7000.conf with 7002 and generate redis_7002.conf file
[[email protected] config]# redis-server /opt/config/redis_7000.conf # Specify the configuration file to start the redis server node
[[email protected] config]# redis-server /opt/config/redis_7001.conf # Specify the configuration file to start the redis server node
[[email protected] config]# redis-server /opt/config/redis_7002.conf # Specify the configuration file to start the redis server node
[[email protected] config]# ps aux | grep redis-server # View the redis-server process running
Root 2444 0.1 0.5 142904 5328 ? Ssl 19:38 0:00 redis-server *:7000 [cluster]
Root 2475 0.0 0.5 142904 5328 ? Ssl 19:39 0:00 redis-server *:7001 [cluster]
Root 2479 0.2 0.5 142904 5328 ? Ssl 19:39 0:00 redis-server *:7002 [cluster]
Root 2483 0.0 0.0 112648 964 pts/0 R+ 19:39 0:00 grep --color=auto redis-server

3.2 Take the first step on the 192.168.81.101 virtual machine, generate three configuration files, and start the Redis server

[[email protected] config]# redis-server /opt/config/redis_7000.conf # Specify the configuration file to start the redis server node
[[email protected] config]# redis-server /opt/config/redis_7001.conf # Specify the configuration file to start the redis server node
[[email protected] config]# redis-server /opt/config/redis_7002.conf # Specify the configuration file to start the redis server node
[[email protected] config]# ps aux | grep redis-server # View the process running of redis-server
Root 1704 0.1 0.2 142916 5344 ? Ssl 19:41 0:00 redis-server *:7000 [cluster]
Root 1736 0.0 0.2 142916 5344 ? Ssl 19:41 0:00 redis-server *:7001 [cluster]
Root 1740 0.0 0.2 142916 5340 ? Ssl 19:42 0:00 redis-server *:7002 [cluster]

3.3 Viewing the information for the cluster node on a 192.168.81.100 virtual machine

[[email protected] config]# redis-cli -p 7000
127.0.0.1:7000> set hello world #Write command to the current node, failed
(error) CLUSTERDOWN Hash slot not served
127.0.0.1:7000> cluster nodes # View cluster node information, only the information of the current node, and display as the primary node
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed :7000 myself,master - 0 0 0 connected
127.0.0.1:7000> cluster info # View cluster information
Cluster_state:fail # cluster is in a failed state
Cluster_slots_assigned:0
Cluster_slots_ok:0 # There are 0 slots in the current cluster.
Cluster_slots_pfail:0
Cluster_slots_fail:0
Cluster_known_nodes:1 # The number of nodes in the current cluster is 1.
Cluster_size:0
Cluster_current_epoch:0
Cluster_my_epoch:0
Cluster_stats_messages_sent:0
Cluster_stats_messages_received:0
127.0.0.1:7000> exit
[[email protected] config]# cd /var/lib/redis/
[[email protected] redis]# ls
Dump.rdb nodes-7000.conf nodes-7001.conf nodes-7002.conf
[[email protected] redis]# cat nodes-7000.conf # View the run_id of the redis-server running on port 7000 and the run_id obtained by executing the cluster nodes command.
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed :0 myself,master - 0 0 0 connected
Vars currentEpoch 0 lastVoteEpoch 0

3.4 Performing the meet operation on 192.168.81.100

[[email protected] redis]# redis-cli -p 7000 cluster meet 127.0.0.1 7001 # Send the meet operation to the redis server of port 7001 through the redis server of port 7000
OK
[[email protected] redis]# redis-cli -p 7000 cluster nodes # View the node information of the cluster through the redis server running on port 7000. The redis server running on port 7001 has been added, and both are master nodes.
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 myself,master - 0 0 0 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539719395866 1 connected
[[email protected] redis]# redis-cli -p 7001 cluster nodes # View the node information of the cluster through the redis server running on port 7001. You can also see the redis server running on port 7000.
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 master - 0 1539719408423 0 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 myself,master - 0 0 1 connected
[[email protected] redis]# redis-cli -p 7002 cluster nodes # View the node information of the cluster through the redis server of port 7002. The redis server running on port 7000 and port 7001 is not in it, because the redis server running on port 7002 is not available. Meet
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a :7002 myself,master - 0 0 0 connected
[[email protected] redis]# redis-cli -p 7000 cluster meet 127.0.0.1 7002 # Send a meal operation to the redis server running on port 7002
OK
[[email protected] redis]# redis-cli -p 7001 cluster nodes # 7002 port running redis server has been added to the cluster
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 master - 0 1539719438785 0 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 master - 0 1539719439689 2 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 myself,master - 0 0 1 connected
[[email protected] redis]# redis-cli -p 7002 cluster nodes
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539719442308 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 master - 0 1539719441301 2 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 myself,master - 0 0 0 connected
[[email protected] redis]# redis-cli -p 7000 cluster meet 192.168.81.101 7002 # Perform a meet operation on the redis server running on port 192.168.81.101:7002
OK
[[email protected] redis]# redis-cli -p 7000 cluster meet 192.168.81.101 7000 # Perform a meet operation on the redis server running on 192.168.81.101: 7000 port
OK
[[email protected] redis]# redis-cli -p 7000 cluster meet 192.168.81.101 7001 # Perform a meet operation on the redis server running on port 192.168.81.101:7001
OK
[[email protected] redis]# redis-cli -p 7000 cluster nodes
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539719546060 5 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539719548113 3 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539719547106 4 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539719544042 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 myself,master - 0 0 2 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 master - 0 1539719545050 0 connected
[[email protected] redis]# redis-cli -p 7002 cluster nodes # View the node information in the cluster and find that all 6 nodes have been added to the current cluster.
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539719554166 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 master - 0 1539719554668 2 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539719555174 4 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539719556180 3 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 myself,master - 0 0 0 connected
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539719557188 5 connected
[[email protected] redis]# redis-cli -p 7002 cluster info # View cluster related information
Cluster_state:fail # cluster status is failed
Cluster_slots_assigned:0
Cluster_slots_ok:0
Cluster_slots_pfail:0
Cluster_slots_fail:0
Cluster_known_nodes:6 # There are 6 known nodes in the cluster
Cluster_size:0
Cluster_current_epoch: 5
Cluster_my_epoch:0
Cluster_stats_messages_sent:507
Cluster_stats_messages_received: 507

3.5 Viewing cluster information on a 192.168.81.101 virtual machine

[[email protected] config]# redis-cli -p 7000 cluster nodes # View the node information of the cluster, the information of all 6 nodes is displayed, and both are master
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539690828453 3 connected
45d79e730593df3216a4236a19c21ff601949449 192.168.81.100:7001 master - 0 1539690825432 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 192.168.81.100:7000 master - 0 1539690826437 2 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 192.168.81.100:7002 master - 0 1539690827448 0 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539690827950 4 connected
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 myself,master - 0 0 5 connected
[[email protected] config]# redis-cli -p 7001 cluster nodes # View the node information of the cluster, the information of all 6 nodes is displayed, and both are master
53911425f4479ce4f054b8b714f4700715f0dc64 127.0.0.1:7002 master - 0 1539690840955 3 connected
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539690842968 5 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 myself,master - 0 0 4 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 192.168.81.100:7002 master - 0 1539690844979 0 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 192.168.81.100:7000 master - 0 1539690841960 2 connected
45d79e730593df3216a4236a19c21ff601949449 192.168.81.100:7001 master - 0 1539690843977 1 connected
[[email protected] config]# redis-cli -p 7002 cluster nodes # View the node information of the cluster, the information of all 6 nodes is displayed, and both are master
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 127.0.0.1:7001 master - 0 1539690847798 4 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 myself,master - 0 0 3 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 192.168.81.100:7000 master - 0 1539690846795 2 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 192.168.81.100:7002 master - 0 1539690843775 0 connected
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539690844780 5 connected
45d79e730593df3216a4236a19c21ff601949449 192.168.81.100:7001 master - 0 1539690845786 1 connected
[[email protected] config]# redis-cli -p 7002 cluster info # View cluster information
Cluster_state:fail # Cluster status is failed
Cluster_slots_assigned:0
Cluster_slots_ok:0
Cluster_slots_pfail:0
Cluster_slots_fail:0
Cluster_known_nodes:6 #6 nodes added to the cluster
Cluster_size:0 # in the cluster
Cluster_current_epoch: 5
Cluster_my_epoch:3
Cluster_stats_messages_sent:413
Cluster_stats_messages_received: 413

3.6 Write a script on the 192.168.81.100 virtual machine to complete the allocation slot

[[email protected] ~]# cd /opt/config/
[[email protected] config]# vi add_slots.sh # Write add_slots.sh script

    #!/bin/bash

    Start=$1
    End=$2
    Port=$3

    For slot in `seq ${start} ${end}`
    Do
        Echo "slot:${slot}"
        Redis-cli -p ${port} cluster addslots ${slot}
    Done
[[email protected] config]# sh add_slots.sh 0 5461 7000 # Run the add_slots.sh script to assign slots 0 to 5461 to the redis server node of 192.168.81.100:7000
Slot:0
OK
Slot:1
OK
Slot: 2
OK
Slot:3
OK
Slot: 4
OK
Slot: 5
OK
...omitted
Slot: 5459
OK
Slot: 5460
OK
Slot: 5461
OK
[[email protected] config]# redis-cli -p 7000 cluster info # View cluster cluster information
Cluster_state: ok # cluster status is OK
Cluster_slots_assigned: 5462 # There are already 5462 data slots in the cluster
Cluster_slots_ok: 5462 # 5462 slots have a status of 0K
Cluster_slots_pfail:0
Cluster_slots_fail:0
Cluster_known_nodes:6 #6 nodes added 6 nodes
Cluster_size:1 # The size of the cluster is 1
Cluster_current_epoch: 5
Cluster_my_epoch: 2
Cluster_stats_messages_sent: 2237
Cluster_stats_messages_received: 2237
[[email protected] config]# redis-cli -p 7000 cluster nodes # View information about nodes in the cluster
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539720483326 5 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539720484336 3 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539720485346 4 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539720482314 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 myself,master - 0 0 2 connected 0-5461 # 192.168.81.100: The redis server running on port 7000 has been assigned slots 0 to 5461, and other nodes have not allocated slots.
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 master - 0 1539720486351 0 connected
[[email protected] config]# redis-cli -p 7002 cluster nodes
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539720507768 1 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 master - 0 1539720509782 2 connected 0-5461
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539720510789 4 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539720508776 3 connected
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 myself,master - 0 0 0 connected
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539720511799 5 connected
[[email protected] config]# sh add_slots.sh 5462 10922 7001 # Run the add_slots.sh script and assign slots 5462 to 10922 to the redis server running on port 7001.
[[email protected] config]# sh add_slots.sh 10923 16383 7002 # Run the add_slots.sh script and assign slots 10923 to 16383 to the redis server running on port 7002.
[[email protected] config]# redis-cli -p 7000 cluster nodes # View node information for the cluster
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539720810075 5 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 master - 0 1539720807558 3 connected
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 192.168.81.101:7001 master - 0 1539720804033 4 connected
45d79e730593df3216a4236a19c21ff601949449 127.0.0.1:7001 master - 0 1539720809067 1 connected 5462-10922 # 7001 port running redis server slot number 5462 to 10922 slot
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 127.0.0.1:7000 myself,master - 0 0 2 connected 0-5461 # 7000 port running redis server slot number 0 to 5461 slot
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 127.0.0.1:7002 master - 0 1539720808061 0 connected 10923-16383 # 7002 port running redis server slot number is 10922 to 16383 slot
[[email protected] config]# redis-cli -p 7000 cluster info # View cluster information
Cluster_state: ok # cluster status is ok
Cluster_slots_assigned:16384 # The cluster has been assigned 16384 slots
Cluster_slots_ok: 16384 # There are 16384 slots in the cluster with the status ok
Cluster_slots_pfail:0
Cluster_slots_fail:0
Cluster_known_nodes:6 # cluster has 6 nodes
Cluster_size:3 # cluster size is 3
Cluster_current_epoch: 5
Cluster_my_epoch: 2
Cluster_stats_messages_sent: 2950
Cluster_stats_messages_received: 2950
[[email protected] config]# redis-cli -p 7001 cluster info
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: 5
Cluster_my_epoch:1
Cluster_stats_messages_sent:3158
Cluster_stats_messages_received:3158
[[email protected] config]# redis-cli -p 7002 cluster info
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: 5
Cluster_my_epoch:0
Cluster_stats_messages_sent: 2828
Cluster_stats_messages_received: 2828
[[email protected] config]# redis-cli -p 7000
127.0.0.1:7000> set hello world # successfully write data to the cluster
OK
127.0.0.1:7000> config get cluster* # Get the configuration information of the cluster
1) "cluster-node-timeout"
2) "15000"
3) "cluster-migration-barrier"
4) "1"
5) "cluster-slave-validity-factor"
6) "10"
7)
"cluster-require-full-coverage"
8) "no"
127.0.0.1:7000> exit

3.7 Operating on a 192.168.81.101 virtual machine

[[email protected] config]# redis-cli -p 7002 cluster nodes # View node information of the cluster, both are master
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 127.0.0.1:7001 master - 0 1539693824725 4 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 myself,master - 0 0 3 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 192.168.81.100:7000 master - 0 1539693826743 2 connected 0-5461
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 192.168.81.100:7002 master - 0 1539693829260 0 connected 10923-16383
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 master - 0 1539693830266 5 connected
45d79e730593df3216a4236a19c21ff601949449 192.168.81.100:7001 master - 0 1539693828252 1 connected 5462-10922
[[email protected] config]# redis-cli -p 7000 cluster replicate d20aa403c5d7d9507adcc4ef6132c14f3c9486ed # Make the 192.168.81.101: 7000 port running redis server as 192.168.81.100: 7000 port running redis server master
OK
[[email protected] config]# redis-cli -p 7001 cluster replicate 45d79e730593df3216a4236a19c21ff601949449
OK
[[email protected] config]# redis-cli -p 7002 cluster replicate e5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a
OK
[[email protected] config]# redis-cli -p 7002 cluster nodes # View node information of the cluster
Bb88f0996503bac3b222b9cc4ec25139ad34ed3a 127.0.0.1:7001 slave 45d79e730593df3216a4236a19c21ff601949449 0 1539693962338 4 connected
53911425f4479ce4f054b8b714f4700715f0dc64 192.168.81.101:7002 myself,slave e5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 0 0 3 connected
D20aa403c5d7d9507adcc4ef6132c14f3c9486ed 192.168.81.100:7000 master - 0 1539693958297 2 connected 0-5461
E5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a 192.168.81.100:7002 master - 0 1539693960324 0 connected 10923-16383
C96589b19b8ff5d9d286d470b8efff9a540726d8 192.168.81.101:7000 slave d20aa403c5d7d9507adcc4ef6132c14f3c9486ed 0 1539693961329 5 connected
45d79e730593df3216a4236a19c21ff601949449 192.168.81.100:7001 master - 0 1539693963347 1 connected 5462-10922
[[email protected] config]# redis-cli -p 7002 cluster slots # View the relationship between slots and nodes in the cluster
1) 1) (integer) 0
   2) (integer) 5461
   3) 1) "192.168.81.100"
      2) (integer) 7000
      3) "d20aa403c5d7d9507adcc4ef6132c14f3c9486ed"
   4) 1) "192.168.81.101"
      2) (integer) 7000
      3) "c96589b19b8ff5d9d286d470b8efff9a540726d8"
2) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "192.168.81.100"
      2) (integer) 7002
      3) "e5ea887c98e79ef2b2205d6cc1d7ac5cfe936d9a"
   4) 1) "192.168.81.101"
      2) (integer) 7002
      3) "53911425f4479ce4f054b8b714f4700715f0dc64"
3) 1) (integer) 5462
   2) (integer) 10922
   3) 1) "192.168.81.100"
      2) (integer) 7001
      3) "45d79e730593df3216a4236a19c21ff601949449"
   4) 1) "127.0.0.1"
      2) (integer) 7001
      3) "bb88f0996503bac3b222b9cc4ec25139ad34ed3a"

3.8 Writing data to the cluster

[[email protected] config]# redis-cli -c -p 7000127.0.0.1:7000> set hello worldOK127.0.0.1:7000> exit

4. Advantages

Can deeply understand the Redis Cluster architecture

5. Disadvantages

Easy to make mistakes, not recommended in production environments

Highly available Redis (10): Redis Native Command Build cluster