redis cluster: manual and automatic

Manual creation:

Environment description: A machine starts up six nodes, three master nodes and three slave nodes.
Installation:
tar -zxvf redis-3.2.10.tar.gz
mv redis-3.2.10 /usr/local/redis
yum install gcc* tcl -y
make && make test
Modify profile:
vi /usr/local/redis/redis.conf

**Where to change**
daemonize yes
port 7000
cluster-enabled yes
cluster-config-file nodes-7000.conf . //This number is best equal to your port number
cluster-node-timeout 5000

Mkdir/usr/local/cluster-test/ //Copy the configuration file and modify the port and parameters

**stay/usr/local/cluster-test/Create under**
mkdir 7000
mkdir 7001
mkdir 7002
mkdir 7003
mkdir 7004
mkdir 7005

Start the service:

./redis-server /usr/local/cluster-test/7000/redis.conf
./redis-server /usr/local/cluster-test/7001/redis.conf
./redis-server /usr/local/cluster-test/7002/redis.conf
./redis-server /usr/local/cluster-test/7003/redis.conf
./redis-server /usr/local/cluster-test/7004/redis.conf
./redis-server /usr/local/cluster-test/7005/redis.conf

netstat -anput | grep redis
[root@localhost src]# ./redis-cli -h 127.0.0.1 -p 7000

127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7000
127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7001
127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7002
127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7003
127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7004
127.0.0.1:7000> CLUSTER MEET 127.0.0.1 7005
127.0.0.1:7000> CLUSTER NODES
127.0.0.1:7000> CLUSTER INFO . //cluter starts with fail

Allocate slot points to three primary nodes:

redis-cli -h 127.0.0.1 -p 7000 cluster addslots {0..5461}
redis-cli -h 127.0.0.1 -p 7001 cluster addslots {5462..10922}
redis-cli -h 127.0.0.1 -p 7002 cluster addslots {10923..16383}

Set slave node:
[root@localhost src]# ./redis-cli -p 7003
127.0.0.1:7003> CLUSTER REPLICATE
8573e44492c6ba0713e36545202459974cc18cf7
[root@localhost src]# ./redis-cli -p 7004
127.0.0.1:7004> CLUSTER REPLICATE
59d75c9a0b599265d0ac123cc99f18050df5afa3
[root@localhost src]# ./redis-cli -p 7005
127.0.0.1:7005> CLUSTER REPLICATE
607f5472bdd9f581ad16b960244ee7ba18fb5a1f
[root@localhost src]# ./redis-cli -p 7000
127.0.0.1:7000> CLUSTER INFO

cluster_state:ok //Success
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:3
cluster_stats_messages_sent:7306
cluster_stats_messages_received:7306

Auto-create:

Environment description: A machine starts up six nodes, three master nodes and three slave nodes.
Installation:
tar -zxvf redis-3.2.10.tar.gz
mv redis-3.2.10 /usr/local/redis
yum install gcc* tcl -y
make && make test
Modify profile:
vi /usr/local/redis/redis.conf

daemonize yes
port 7000
cluster-enabled yes
cluster-config-file nodes-7000.conf . //This number is best equal to your port number
cluster-node-timeout 5000
appendonly yes

Mkdir/usr/local/cluster-test/ //Copy the configuration file and modify the port and parameters

mkdir 7000
mkdir 7001
mkdir 7002
mkdir 7003
mkdir 7004
mkdir 7005

Start the service:

redis-server /usr/local/cluster-test/7000/redis.conf
redis-server /usr/local/cluster-test/7001/redis.conf
redis-server /usr/local/cluster-test/7002/redis.conf
redis-server /usr/local/cluster-test/7003/redis.conf
redis-server /usr/local/cluster-test/7004/redis.conf
redis-server /usr/local/cluster-test/7005/redis.conf

[root@localhost ~]#netstat -anput | grep redis
Clustering six nodes together
The command needed is redis-trib.rb, an official ruby command that operates on redis cluster s
So you need to install ruby on your machine.Let's try this command first:
[root@web3 7005]# yum -y install rpm-build openssl openssl-devel
[root@localhost ruby]# tar -zxvf ruby-2.3.1.tar.gz
[root@localhost ruby]#./configure --prefix=/usr/local/ruby
[root@localhost ruby]#make && make install
[root@localhost ruby]#ln -s /usr/local/ruby/bin/* /usr/local/bin/
[root@localhost ~]# ln /usr/local/redis/src/redis-trib.rb /usr/local/bin/
[root@localhost ~]#gem install redis-3.3.0.gem
[root@localhost ~]# gem list redis
Because we are creating a new cluster, we use the create command here. --replicas 1 parameter to create one for each primary node
The other parameters are the address collection of the instance.

[root@localhost src]# redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005

Creating cluster
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7002: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7005: OK
Performing hash slots allocation on 6 nodes...
Using 3 masters:
127.0.0.1:7000
127.0.0.1:7001
127.0.0.1:7002
Adding replica 127.0.0.1:7003 to 127.0.0.1:7000
Adding replica 127.0.0.1:7004 to 127.0.0.1:7001
Adding replica 127.0.0.1:7005 to 127.0.0.1:7002
M: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots:0-5460 (5461 slots) master
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:5461-10922 (5462 slots) master
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:10923-16383 (5461 slots) master
S: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
replicates 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
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 127.0.0.1:7000)
M: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots:0-5460 (5461 slots) master
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:5461-10922 (5462 slots) master
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:10923-16383 (5461 slots) master
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots: (0 slots) master
replicates 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4
M: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) master
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
M: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) master
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
[OK] All nodes agree about slots configuration.
Check for open slots...
Check slots coverage...
[OK] All 16384 slots covered.
Redis-trib will prompt you what configuration you have made, enter yes to accept. The cluster is configured and joined, meaning, instance
It will start after mutual communication.
Test the state of the cluster:
[root@localhost 7000]# redis-trib.rb check 127.0.0.1:7000
You can see three primary nodes and three slave nodes.Each node is in a successful connection state
The three primary nodes [M] are:
7000 (3707debcbe7be66d4a1968eaf3a5ffaf4308efa4)
7001 (cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c)
7002 (dfa0754c7854a874a6ebd2613b86140ad97701fc)
The three slave nodes [S] are:
7003 (d2237fdcfbba672de766b913d1186cebcb6e1761)->7000
7004 (4b4aef8b48c427a3c903518339d53b6447c58b93)->7001
7005 (30858dbf483b61b9838d5c1f853a60beaa4e7afd) ->7002
Test Connection Cluster
The cluster was built successfully just now.According to the characteristics of redis cluster, it is de-centralized, and each node is equal.
So, any node you connect can get and set data. Let's try.redis-cli is the default customer for redis
End tools, starting with the -c parameter, connect to the cluster.Connect any node port:
[root@web3 7000]# redis-cli -c -p 7000
127.0.0.1:7000>
Set a value:
127.0.0.1:7000> set my_name linux
-> Redirected to slot [12803] located at 127.0.0.1:7002
OK
127.0.0.1:7002> get my_name
"linux"
127.0.0.1:7002>
Previous theoretical knowledge has shown that when a key is assigned, it uses the CRC16('my_name')%16384 algorithm.
To calculate which node this key is placed on, 12803 slot s are allocated to 7002 (10923-
16383) on this node.
Redirected to slot [12803] located at 127.0.0.1:7002
The redis cluster takes a straightforward approach, jumping directly to the 7002 node instead of still at its 7000 section
Point.Now we connect 7005 from this node:
[root@web3 7000]# redis-cli -c -p 7005

127.0.0.1:7005> get my_name
-> Redirected to slot [12803] located at 127.0.0.1:7002
"linux"
127.0.0.1:7002>
//We also get the value of my_name, which also jumps to 7002.Let's try some more
//To:
127.0.0.1:7002> set age 123
-> Redirected to slot [741] located at 127.0.0.1:7000
OK
127.0.0.1:7000> set height 565
-> Redirected to slot [8223] located at 127.0.0.1:7001
OK
127.0.0.1:7001> set sex 1
-> Redirected to slot [2584] located at 127.0.0.1:7000
OK
127.0.0.1:7000> set home china
-> Redirected to slot [10814] located at 127.0.0.1:7001
OK
127.0.0.1:7001> set city shanghai
-> Redirected to slot [11479] located at 127.0.0.1:7002
OK
127.0.0.1:7002> set citylocate shanghaipudong
OK
127.0.0.1:7001> set wsdwxzx hhh
-> Redirected to slot [15487] located at 127.0.0.1:7002
OK
127.0.0.1:7002> zadd erew 333 rrr
-> Redirected to slot [10576] located at 127.0.0.1:7001
(integer) 1
127.0.0.1:7000> zrange erew 0 -1
-> Redirected to slot [10576] located at 127.0.0.1:7001
1) "rrr"
127.0.0.1:7001>
128.~~~~
//As you can see, all data will jump to storage at the three primary nodes, 7000-7002.
//Node hang in test cluster
//Above we set up a cluster.Three primary nodes [7000-7002] provide data storage coarseness and read, and three slave nodes
[7003-7005]Is responsible for[7000-7002]Synchronize data to your own node, let's take a look
[7003-7005]Of appendonly.aof Content.See if this is not the case:
`[root@web3 7005]# cd /usr/local/cluster-test/7003`
`[root@web3 7003]# vi appendonly.aof`
*2
$6
SELECT
$1
0
*3
$3
set
$3
age
$3
123
*3
$3
set
$3
sex
$1
1
*3
$3
set
$3
job
$3
php
//Let's see, it's really data synchronized from 7000 nodes, and 7004, 7005 are also.
//Next, let's simulate one of the Master master servers hanging up.
`[root@web3 7003]# ps -ef|grep redis`
root 11380 1 0 07:37 ? 00:00:03 redis-server *:7000 [cluster]
root 11384 1 0 07:37 ? 00:00:03 redis-server *:7001 [cluster]
root 11388 1 0 07:37 ? 00:00:03 redis-server *:7002 [cluster]
root 11392 1 0 07:37 ? 00:00:03 redis-server *:7003 [cluster]
root 11396 1 0 07:37 ? 00:00:04 redis-server *:7004 [cluster]
root 11400 1 0 07:37 ? 00:00:03 redis-server *:7005 [cluster]
//Okay, install the previous theory, the 7000 master node is hung up, then only 7003 slave nodes are available for 7000 at this time.
//Definitely 7003 will be elected Master Node:
`[root@web3 7003]# kill 11380`
`[root@web3 7003]# redis-trib.rb check 127.0.0.1:7000`
Connecting to node 127.0.0.1:7000: [ERR] Sorry, can't connect to node
127.0.0.1:7000
`[root@web3 7003]# redis-trib.rb check 127.0.0.1:7001`
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7002: OK
 Performing Cluster Check (using node 127.0.0.1:7001)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots:0-5460 (5461 slots) master
0 additional replica(s)
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:10923-16383 (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.
//Looking at it, there are three M nodes above. True, 7003 has been selected as the main node instead of 7000.Then we
//To get data that previously had 7000 nodes:
`[root@web3 7003]# redis-cli -c -p 7001`
127.0.0.1:7001> get sex
 Redirected to slot [2584] located at 127.0.0.1:7003
"1"
127.0.0.1:7003>
//The data was not lost, it was taken from 7003.
//Let's simulate a restart of 7000 nodes, so will it automatically join the cluster?So, 7000
//What role does this node play?Let's try: Restart 7000 nodes:
[root@web3 7003]# cd ../7000
[root@web3 7000]# ll
total 56
-rw-r--r-- 1 root root 114 Oct 17 08:16 appendonly.aof
-rw-r--r-- 1 root root 43 Oct 17 08:37 dump.rdb
-rw-r--r-- 1 root root 745 Oct 17 08:00 nodes.conf
-rw-r--r-- 1 root root 41550 Oct 17 07:37 redis.conf
[root@web3 7000]# redis-server redis.conf
//Now that you've started, let's check the cluster again:
redis-trib.rb check 127.0.0.1:7001
`[root@web3 7000]# redis-trib.rb check 127.0.0.1:7001`
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7002: OK
 Performing Cluster Check (using node 127.0.0.1:7001)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots:0-5460 (5461 slots) master
1 additional replica(s)
S: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots: (0 slots) slave
replicates d2237fdcfbba672de766b913d1186cebcb6e1761
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:10923-16383 (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.
//Look, 7000 nodes are up, but it acts as the slave node of 7003.

-----

de 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7002: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
 Performing Cluster Check (using node 127.0.0.1:7006)
M: efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006
slots: (0 slots) master
0 additional replica(s)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots: (0 slots) slave
replicates d2237fdcfbba672de766b913d1186cebcb6e1761
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:10923-16383 (5461 slots) master
1 additional replica(s)
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
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.
How many slots do you want to move (from 1 to 16384)?
//It tells us how many slot s we need to migrate to 7006, so let's figure it out: 16384/4 = 4096, that is,
//To balance the distribution, we need to move 4096 slots to 7006.Then enter 4096:
How many slots do you want to move (from 1 to 16384)? 4096
What is the receiving node ID?
//It also tells us what node ID s are accepted, 7006 IDS we can see from above are
efc3131fbdc6cf929720e0e0f7136cae85657481 :
What is the receiving node ID? efc3131fbdc6cf929720e0e0f7136cae85657481
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:
//Then redis-trib asks you which section to repartition the source node from
//Remove 4096 hash slots from the point and move them over 7006 nodes.
//If we do not intend to remove a specified number of hash slots from a particular node, we can enter all to redis-trib.
//In this way, all the primary nodes in the cluster will become source nodes, and redis-trib will be pulled out of each source node
//Partial hash slots, up to 4096, then moved to 7006 nodes: Source node #1:all then opens
//Start migrating and ask if you are sure:
Moving slot 1359 from d2237fdcfbba672de766b913d1186cebcb6e1761
Moving slot 1360 from d2237fdcfbba672de766b913d1186cebcb6e1761
Moving slot 1361 from d2237fdcfbba672de766b913d1186cebcb6e1761
Moving slot 1362 from d2237fdcfbba672de766b913d1186cebcb6e1761
Moving slot 1363 from d2237fdcfbba672de766b913d1186cebcb6e1761
Moving slot 1364 from d2237fdcfbba672de766b913d1186cebcb6e1761
Do you want to proceed with the proposed reshard plan (yes/no)?
//After entering yes and pressing Enter, redis-trib will officially begin the repartitioning operation, specifying the hash
//Slots move from source node to 7006 node one by one.
//After the migration is complete, let's check:
[root@web3 7006]# redis-trib.rb check 127.0.0.1:7000
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7002: OK
Performing Cluster Check (using node 127.0.0.1:7000)
S: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots: (0 slots) slave
replicates d2237fdcfbba672de766b913d1186cebcb6e1761
M: efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006
slots:0-1364,5461-6826,10923-12287 (4096 slots) master
0 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots:1365-5460 (4096 slots) master
1 additional replica(s)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:6827-10922 (4096 slots) master
1 additional replica(s)
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:12288-16383 (4096 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.
//We focus on 7006: 0-1364,5461-6826,10923-12287 (4096 slots) which were originally on other nodes
//The slot chopper migrated to 7006.Originally, it was just a movement of intervals, not an overall movement of convergence, let's see
//Is there any data?
[root@web3 7006]# redis-cli -c -p 7006
127.0.0.1:7006> keys *
1) "city"
2) "age"
3) "citylocate"
127.0.0.1:7006> get city
"shanghai"
//Great. There's already data.
//Create a new 7007 slave node, as the slave node of 7006 we will create a new 7007 node, similar steps, save first
//Skipped.Once it's built, start up and let's see how to add it to the slave nodes in the cluster:
[root@web3 7007]# redis-trib.rb add-node --slave 127.0.0.1:7007 127.0.0.1:7000
add-node Add when--slave Representation is added to the slave node, but this addition is random.Commands here
//Rows are exactly the same as we used when adding a new primary server, so we did not specify which primary server to add to
//Add a copy.In this case, redis-trib will use 7007 as a secondary to a random primary server with fewer copies
//Ben.
//Then, whose slave node it will be, it should be 7006, because 7006 has not yet slave node.We're running.
[root@web3 7007]# redis-trib.rb add-node --slave 127.0.0.1:7007 127.0.0.1:7000
...
...
[OK] All 16384 slots covered.
Automatically selected master 127.0.0.1:7006
Connecting to node 127.0.0.1:7007: OK
Send CLUSTER MEET to node 127.0.0.1:7007 to make it join the cluster.
Waiting for the cluster to join.
Configure node as replica of 127.0.0.1:7006.
[OK] New node added correctly.
//As mentioned above, 7006 was automatically selected as the master node.And it succeeded.Let's check:
[root@web3 7007]# redis-trib.rb check 127.0.0.1:7000
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7007: OK
Connecting to node 127.0.0.1:7002: OK
Performing Cluster Check (using node 127.0.0.1:7000)
S: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots: (0 slots) slave
replicates d2237fdcfbba672de766b913d1186cebcb6e1761
M: efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006
slots:0-1364,5461-6826,10923-12287 (4096 slots) master
1 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots:1365-5460 (4096 slots) master
1 additional replica(s)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:6827-10922 (4096 slots) master
1 additional replica(s)
S: 86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007
slots: (0 slots) slave
replicates efc3131fbdc6cf929720e0e0f7136cae85657481
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:12288-16383 (4096 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.
//Sure enough, 7007 joined the slave nodes of 7006.
//Can't you specify a primary node row?Certainly.Let's build another 7008 node.
redis-trib.rb add-node --slave --master-id
efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7008 127.0.0.1:7000
--master-id Represents the specified primary node node id. The primary node 7006 is specified here.
 Configure node as replica of 127.0.0.1:7006.
[OK] New node added correctly.
//Tips us that we have come as an accessory to 7006, that is, from the node that joined 7006. As such, 7006 has
2 Let's look at the following:
redis-cli -c -p 7008 cluster nodes |grep
efc3131fbdc6cf929720e0e0f7136cae85657481
86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007 slave
efc3131fbdc6cf929720e0e0f7136cae85657481 0 1445089507786 8 connected
efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006 master - 0 1445089508289
8 connected 0-1364 5461-6826 10923-12287
44321e7d619410dc4e0a8745366610a0d06d2395 127.0.0.1:7008 myself,slave
efc3131fbdc6cf929720e0e0f7136cae85657481 0 0 0 connected
//Let's filter it out and see if 7007 and 7008 are slave nodes of 7006.
//Let's do another experiment. I'll kill 7006 to see who will become the main node of 7007 and 7008:
[root@web3 7008]# ps -ef|grep redis
root 11384 1 0 09:56 ? 00:00:16 redis-server *:7001 [cluster]
root 11388 1 0 09:56 ? 00:00:16 redis-server *:7002 [cluster]
root 11392 1 0 09:56 ? 00:00:16 redis-server *:7003 [cluster]
root 11396 1 0 09:56 ? 00:00:15 redis-server *:7004 [cluster]
root 11400 1 0 09:56 ? 00:00:15 redis-server *:7005 [cluster]
root 12100 1 0 11:01 ? 00:00:11 redis-server *:7000 [cluster]
root 12132 1 0 11:28 ? 00:00:11 redis-server *:7006 [cluster]
root 12202 1 0 13:14 ? 00:00:02 redis-server *:7007 [cluster]
root 12219 1 0 13:39 ? 00:00:00 redis-server *:7008 [cluster]
root 12239 8259 0 13:49 pts/0 00:00:00 grep redis
[root@web3 7008]# kill 12132
[root@web3 7008]# redis-cli -c -p 7008
127.0.0.1:7008> get ss5rtr
Redirected to slot [1188] located at 127.0.0.1:7007
"66"
127.0.0.1:7007> cluster nodes
efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006 master,fail -
1445089780668 1445089779963 8 disconnected
d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003 master - 0 1445089812195
7 connected 1365-5460
30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005 slave
dfa0754c7854a874a6ebd2613b86140ad97701fc 0 1445089813710 3 connected
86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007 myself,master - 0 0 10
connected 0-1364 5461-6826 10923-12287
cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001 master - 0 1445089814214
2 connected 6827-10922
4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004 slave
cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 0 1445089812701 2 connected
44321e7d619410dc4e0a8745366610a0d06d2395 127.0.0.1:7008 slave
86d05e7c2b197dc182b5e71069e791d033cf899e 0 1445089814214 10 connected
3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000 slave
d2237fdcfbba672de766b913d1186cebcb6e1761 0 1445089813204 7 connected
dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002 master - 0 1445089813204
3 connected 12288-16383
127.0.0.1:7007>
7007 Get the chance to be the master node, 7008 becomes the slave node of 7007.Then at this point, restart 7006
//Node, then he becomes a slave node of 7007.
127.0.0.1:7008> cluster nodes
30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005 slave
dfa0754c7854a874a6ebd2613b86140ad97701fc 0 1445089986148 3 connected
86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007 master - 0
1445089986652 10 connected 0-1364 5461-6826 10923-12287
d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003 master - 0
1445089986148 7 connected 1365-5460
cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001 master - 0
1445089987155 2 connected 6827-10922
efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006 slave
86d05e7c2b197dc182b5e71069e791d033cf899e 0 1445089985644 10 connected
44321e7d619410dc4e0a8745366610a0d06d2395 127.0.0.1:7008 myself,slave
86d05e7c2b197dc182b5e71069e791d033cf899e 0 0 0 connected
dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002 master - 0
1445089986652 3 connected 12288-16383
4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004 slave
cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 0 1445089987660 2 connected
3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000 slave
d2237fdcfbba672de766b913d1186cebcb6e1761 0 1445089985644 7 connected
127.0.0.1:7008>
//Removing a primary node adds, affirms, and subtracts. The redis cluster also supports removing nodes, as is the use of redistrib.rb:
redis-trib del-node 127.0.0.1:7000 `<node-id>`
//A little different from adding a new node is to remove the node-id that requires the node.So we're trying to move the 7007 primary node
//Except:
[root@web3 7006]# redis-trib.rb del-node 127.0.0.1:7000
86d05e7c2b197dc182b5e71069e791d033cf899e
Removing node 86d05e7c2b197dc182b5e71069e791d033cf899e from cluster
127.0.0.1:7000
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7007: OK
Connecting to node 127.0.0.1:7008: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7002: OK
[ERR] Node 127.0.0.1:7007 is not empty! Reshard data away and try again.
//Error, it prompted us to say that since there is already data in 7007, it can not be removed, we need to transfer its data first
//Get out.That is to say, you have to re-slice, just like you did when you added a new node above, again with us:
redis-trib.rb reshard 127.0.0.1:7000
//Omitting the trivial because there is too much in the middle simply explains the key steps:
M: 86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007
slots:0-1364,5461-6826,10923-12287 (4096 slots) master
How many slots do you want to move (from 1 to 16384)?
//Tip, how many slots do we have to divide, because there are 4096 slots on 7007, so fill in 4096 here
How many slots do you want to move (from 1 to 16384)? 4096
What is the receiving node ID?
//Tell us which id we need to move to, so fill in 7001:
What is the receiving node ID? cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
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:
//Here's the key, which node it wants us to transfer data from to 7001, because we want to delete 7007
//So, we'll have an id of 7007
Source node #1:86d05e7c2b197dc182b5e71069e791d033cf899e
Source node #2:done
Do you want to proceed with the proposed reshard plan (yes/no)? yes
ok,That's the migration.Let's see if 7007 is empty:
[root@web3 7006]# redis-cli -c -p 7007
127.0.0.1:7007> keys *
(empty list or set)
127.0.0.1:7007> cluster nodes
86d05e7c2b197dc182b5e71069e791d033cf899e 127.0.0.1:7007 myself,master - 0 0 10
connected
//It's empty, okay.Now remove the node:
[root@web3 7006]# redis-trib.rb del-node 127.0.0.1:7000
86d05e7c2b197dc182b5e71069e791d033cf899e
Removing node 86d05e7c2b197dc182b5e71069e791d033cf899e from cluster
127.0.0.1:7000
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7007: OK
Connecting to node 127.0.0.1:7008: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7002: OK
Sending CLUSTER FORGET messages to the cluster...
127.0.0.1:7006 as replica of 127.0.0.1:7001
127.0.0.1:7008 as replica of 127.0.0.1:7001
SHUTDOWN the node.
//Delete succeeded.
//Let's check again: 7007 has been removed and can't be connected.
[root@web3 7006]# redis-trib.rb check 127.0.0.1:7007
Connecting to node 127.0.0.1:7007: [ERR] Sorry, can't connect to node
127.0.0.1:7007
[root@web3 7006]# redis-trib.rb check 127.0.0.1:7008
Connecting to node 127.0.0.1:7008: OK
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7003: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7002: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7000: OK
>>> Performing Cluster Check (using node 127.0.0.1:7008)
S: 44321e7d619410dc4e0a8745366610a0d06d2395 127.0.0.1:7008
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 30858dbf483b61b9838d5c1f853a60beaa4e7afd 127.0.0.1:7005
slots: (0 slots) slave
replicates dfa0754c7854a874a6ebd2613b86140ad97701fc
M: d2237fdcfbba672de766b913d1186cebcb6e1761 127.0.0.1:7003
slots:1365-5460 (4096 slots) master
1 additional replica(s)
M: cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c 127.0.0.1:7001
slots:0-1364,5461-12287 (8192 slots) master
3 additional replica(s)
S: efc3131fbdc6cf929720e0e0f7136cae85657481 127.0.0.1:7006
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
M: dfa0754c7854a874a6ebd2613b86140ad97701fc 127.0.0.1:7002
slots:12288-16383 (4096 slots) master
1 additional replica(s)
S: 4b4aef8b48c427a3c903518339d53b6447c58b93 127.0.0.1:7004
slots: (0 slots) slave
replicates cb5c04b6160c3b7e18cad5d49d8e2987b27e0d6c
S: 3707debcbe7be66d4a1968eaf3a5ffaf4308efa4 127.0.0.1:7000
slots: (0 slots) slave
replicates d2237fdcfbba672de766b913d1186cebcb6e1761
[OK] All nodes agree about slots configuration.
 Check for open slots...
 Check slots coverage...
[OK] All 16384 slots covered.
7006 And 7008 have successfully joined the 7001 cluster.
//Removing one from the node and one from the node is much simpler, because there is no need to consider data migration, we give 7008
//Remove:
[root@web3 7006]# redis-trib.rb del-node 127.0.0.1:7008
44321e7d619410dc4e0a8745366610a0d06d2395
 Removing node 44321e7d619410dc4e0a8745366610a0d06d2395 from cluster
127.0.0.1:7005
Connecting to node 127.0.0.1:7005: OK
Connecting to node 127.0.0.1:7001: OK
Connecting to node 127.0.0.1:7002: OK
Connecting to node 127.0.0.1:7004: OK
Connecting to node 127.0.0.1:7000: OK
Connecting to node 127.0.0.1:7006: OK
Connecting to node 127.0.0.1:7008: OK
Connecting to node 127.0.0.1:7003: OK
 Sending CLUSTER FORGET messages to the cluster...
 SHUTDOWN the node.
[root@web3 7006]# redis-trib.rb check 127.0.0.1:7008
Connecting to node 127.0.0.1:7008: [ERR] Sorry, can't connect to node
127.0.0.1:7008
//Removal was successful.

Tags: Linux Redis Ruby OpenSSL

Posted on Sun, 15 Mar 2020 15:24:32 -0400 by leafface