Shulou(Shulou.com)06/01 Report--

Election of Redis cluster nodes:

When master dies, one of the slave in the cluster will be selected to replace the mater role

Thus the integrity of redis cluster slot is guaranteed.

If one of the mster and its slave is dead, the slot will be incomplete and the whole cluster will be dead.

Cluster node information:

192.168.2.200 6379 > cluster nodes

3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 192.168.2.201 6379 master-0 1527145806504 5 connected 10923-16383

2faf68564a70372cfc06c1afff197019cc6a39f3 192.168.2.201:6380 slave 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 0 1527145805495 5 connected

227f51028bbe827f27b4e40ed7a08fcc7d8df969 192.168.2.200:6380 slave 098e7eb756b6047fde988ab3c0b7189e1724ecf5 0 1527145804485 4 connected

5844b4272c39456b0fdf73e384ff8c479547de47 192.168.2.200 5844b4272c39456b0fdf73e384ff8c479547de47 6379 myself,master-00 3 connected 5461-10922

7119dec91b086ca8fe69f7878fa42b1accd75f0f 192.168.2.100:6380 slave 5844b4272c39456b0fdf73e384ff8c479547de47 0 1527145802468 3 connected

098e7eb756b6047fde988ab3c0b7189e1724ecf5 192.168.2.100 098e7eb756b6047fde988ab3c0b7189e1724ecf5 6379 master-0 1527145803476 1 connected 0-5460

Create 3 new key:

192.168.2.200 6379 > set name zhangsan

OK

192.168.2.200 set age 6379 > 26

-> Redirected to slot [741] located at 192.168.2.100

OK

192.168.2.100Suzhou 6379 > set home beijing

-> Redirected to slot [10814] located at 192.168.2.200

OK

Simulate 192.168.2.100RU 6379 to hang up:

# ps-ef | grep redis

Root 19023 10 15:05? 00:00:01 redis-server 192.168.2.100:6379 [cluster]

Root 19030 10 15:05? 00:00:01 redis-server 192.168.2.100:6380 [cluster]

Root 19127 2912 0 15:13 pts/0 00:00:00 grep-color=auto redis

# kill 19023

Check the status of the cluster node: (you can see that the role of a slave in the cluster becomes master)

# redis-trib.rb check 192.168.2.200:6379

> Performing Cluster Check (using node 192.168.2.200)

M: 5844b4272c39456b0fdf73e384ff8c479547de47 192.168.2.200:6379

Slots:5461-10922 (5462 slots) master

1 additional replica (s)

M: 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 192.168.2.201:6379

Slots:10923-16383 (5461 slots) master

1 additional replica (s)

S: 2faf68564a70372cfc06c1afff197019cc6a39f3 192.168.2.201:6380

Slots: (0 slots) slave

Replicates 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69

M: 227f51028bbe827f27b4e40ed7a08fcc7d8df969 192.168.2.200:6380

Slots:0-5460 (5461 slots) master

0 additional replica (s)

S: 7119dec91b086ca8fe69f7878fa42b1accd75f0f 192.168.2.100:6380

Slots: (0 slots) slave

Replicates 5844b4272c39456b0fdf73e384ff8c479547de47

[OK] All nodes agree about slots configuration.

> Check for open slots...

> Check slots coverage...

[OK] All 16384 slots covered.

To see if the data exists:

# redis-cli-h 192.168.2.200-p 6380-c

192.168.2.200 6380 > keys *

1) "age"

Simulate recovery of failed nodes:

# redis-server redis.conf

Check the status of the cluster node: (after the failed node is restored, will it become master or slave? )

# redis-trib.rb check 192.168.2.200:6379

> Performing Cluster Check (using node 192.168.2.200)

M: 5844b4272c39456b0fdf73e384ff8c479547de47 192.168.2.200:6379

Slots:5461-10922 (5462 slots) master

1 additional replica (s)

M: 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69 192.168.2.201:6379

Slots:10923-16383 (5461 slots) master

1 additional replica (s)

S: 2faf68564a70372cfc06c1afff197019cc6a39f3 192.168.2.201:6380

Slots: (0 slots) slave

Replicates 3ff3a74f9dc41f8bc635ab845ad76bf77ffb0f69

M: 227f51028bbe827f27b4e40ed7a08fcc7d8df969 192.168.2.200:6380

Slots:0-5460 (5461 slots) master

1 additional replica (s)

S: 7119dec91b086ca8fe69f7878fa42b1accd75f0f 192.168.2.100:6380

Slots: (0 slots) slave

Replicates 5844b4272c39456b0fdf73e384ff8c479547de47

S: 098e7eb756b6047fde988ab3c0b7189e1724ecf5 192.168.2.100:6379

Slots: (0 slots) slave

Replicates 227f51028bbe827f27b4e40ed7a08fcc7d8df969

[OK] All nodes agree about slots configuration.

> Check for open slots...

> Check slots coverage...

[OK] All 16384 slots covered.

Summary: after master:192.168.2.100:6379 downtime

Slave:192.168.2.200:6380 took its place and became a master character.

When 192.168.2.100 master 6379 failed to recover, it was not restored to the role of Rol

But played the role of slave.

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