Redis [NEW] 2 different ip of redis node shall not master-salve of each other when create cluster

The problem/use-case that the feature addresses

“redis-cli --cluster create” , since create the cluster can ensure master node distribute to different ip, is there any possible to optimization algorithm make 2 different ip of redis node shall not master-salve of each other

that will improve the cluster stable.

Description of the feature

Expected cluster structure

Unexpected cluster structure

Alternatives you've considered

static int clusterManagerCommandCreate(int argc, char **argv); add more check with the slave node.

Additional information

Any additional information that is relevant to the feature request.

Comment From: chenshi5012

if 192.168.1.1 and 192.168.1.2 down, the first structure will remain 75% data userful, but the second mode will just remain 50% data.

Comment From: Jeremy-Run

This scheme may increase the cost of cluster

Comment From: chenshi5012

This scheme may increase the cost of cluster replicas may increase the cost of cluster.

but Adjust the active/standby distribution，the same machine resources， will improve the stable while Power failure issue happend. right?

Comment From: chenshi5012

$ ./redis-cli.exe --cluster create 127.0.0.1:30001 127.0.0.4:30003 127.0.0.2:30001 127.0.0.1:30002 127.0.0.4:30001 127.0.0.4:30005 127.0.0.3:30002 127.0.0.2:30002 --cluster-replicas 1

Performing hash slots allocation on 8 nodes... Master[0] -> Slots 0 - 4095 Master[1] -> Slots 4096 - 8191 Master[2] -> Slots 8192 - 12287 Master[3] -> Slots 12288 - 16383 Adding replica 127.0.0.4:30001 to 127.0.0.1:30001 Adding replica 127.0.0.2:30002 to 127.0.0.4:30003 Adding replica 127.0.0.4:30005 to 127.0.0.2:30001 Adding replica 127.0.0.1:30002 to 127.0.0.3:30002

============ we can see that 127.0.0.2 and 127.0.0.4 become master-slave to each other